CdZnTe - OSTI.GOV

45
KAREI/AR-886/2011 CdZnTe Analysis of Study Trend of Growth and Characterization of CdZnTe Single Crystal

Transcript of CdZnTe - OSTI.GOV

Page 1: CdZnTe - OSTI.GOV

KAREI/AR-886/2011

CdZnTe

Analysis of Study Trend of Growth and Characterization of

CdZnTe Single Crystal

Page 2: CdZnTe - OSTI.GOV

*11

^ MZLXiS ^|#7|# CdZnTe Eil§ ^

M2LAi^ AH#°hL|

2011 ^ 51 27S

^*1*h o|^S

6|-^5:

a#~r

o"o A-] A|-:

Page 3: CdZnTe - OSTI.GOV

a 2

CdZnTe (CZT) £|S7|7|, M°hS^ #£| ^7^* ygoj|o|

§§°^ M #a^0| &o^|2L oi-b y^Xii ^XH0|EK EHf^£| Eil

3# 2%op| ?|6HXlb #0]0^ # ^ 7\J\ £JH\7[ ^O^OIOLK 2L#1£|

Eil^oii EH oh Ahg^j #EH#|0H CEHEH h^a||^o|| eh

oh £!A||7||?Ho^ S^ho| 0| = 0]X|2L OIEK

£ M2LAl01|Alb CZT EM§ #$M| EHoH

7|#6|-2LXH ohEj-. yxi, CZT°| ^^°h Phase diagram^ 7|o|o_h ^§oh

CZT£| compensation 7^Z\ #^2H *^| iM*!°! #E|, 2\*\™

ohEH. EH#o^ Eil^s cHotoh Hhgs #o|, a|o||

1 4 5i-b ##0j| ^0] 7|#6H2LXH oh EH. SE°h !3°l SIS

7|^E|| m^^oi lAial ^SohEh □HA|E|a^, SSg EMS°I

l7H6Hb 4# ^SS 7IS6H2LXH oh Eh

L^hA|

r^S

1

Page 4: CdZnTe - OSTI.GOV

Summary

CdZnTe (CZT) alloys are very important semiconducting compounds due to their use in

several strategic applications in medical, space, and security devices, especially, radiation

detector. Specific problems of the bulk crystal growth are still to be solved. However, since

industries require excellent bulk CZT crystals, a strong effort is being organized worldwide to

optimize the growth process and obtain better material.

This report presents the study trend of the bulk CZT crystal growth and characteristics.

After the first section where the problems connected to the complicated phase diagram of

CZT are presented, the second section describes the various general physical and chemical

properties, together with the compensation problems of the CZT material. In the third section,

various growth methods are described, paying attention to the defects generated in the

different cases. Further, the annealing process which is an essential step for improving the

crystal quality is described. In the last section, the general material characterization methods

are presented, as a scientific approach for assessing the quality of the bulk crystal.

u

Page 5: CdZnTe - OSTI.GOV

Summary

........

Contents.

3^ 4^

ii

iii

iv

v

l. A1# ..............................................................................................................................................1

n.CZT yiy #9.............................................................................................................2

1. Phase Diagram.............................................................................................................................. 2

2. #a|, ^otTH ................................................................................................................... 3

3. Compensation ............................................................................................................................. 6

m. 9#...................................................................................................................................10

1. 9& io

2. 9^ 13

3. 9& 15

4. 9^ 20

5. l^a|.............................................................................................................................24

IV. #9 %7\.........................................................................................................................27

V. 1#...............................................................................................................................................31

Reference 32

Page 6: CdZnTe - OSTI.GOV

Contents

Summary (Korean)

Summary...............

Contents(Korean).

Contents................

Figure contents.....

i

ii

iii

iv

v

I. Introduction .................................................................................................................................1

II. Properties of CZT Crystals....................................................................................................... 2

1. Phase Diagram.............................................................................................................................. 2

2. Chemical and Physical Properties..............................................................................................3

3. Compensation Problems ............................................................................................................6

HI. Crystal Growth........................................................................................................................... 10

1. General Problems and Initial Conditions................................................................................10

2. Modeling of the Growth............................................................................................................ 13

3. Methods of Growth....................................................................................................................15

4. Growth Defects..........................................................................................................................20

5. Annealing....................................................................................................................................24

IV. Characterization........................................................................................................................27

V. Conclusions..................................................................................................................................31

Reference........................................................................................................................................... 32

IV

Page 7: CdZnTe - OSTI.GOV

Figure Contents

Fig. 1 T-x projections of the Cdo.9Zno.1Te solidus........................................................................... 2

Fig. 2 The native defects, impurities, and defect complexes, which were detected in semi-

insulating Cdi-xZnxTe with the value of their ionization energy levels............................. 7

Fig. 3 Axial temperature profile versus height for graphite(G) and PBN(P) crucibles at

different growth stages(Gl-G4 and P1-P4).......................................................................... 15

Fig. 4 Brigdman method with the Pt support, which acts as a cold finger during the growth of

bulk CZT crystals.................................................................................................................... 17

Fig. 5 The multi tube Physical vapor transport...............................................................................19

Fig. 6 The typical surface morphologies of CZT {111 }B samples in (a, c) and {211 }B

samples in (b, d) etched by Everson solution......................................................................22

Fig. 7 IR microscope image of a CZT sample before (a) and after(b) annealing at high

temperature in Cd-rich ambient............................................................................................. 25

Fig. 8 Four types of IR transmission spectra: (a) descending type, (b) ascending type, (c) low

straight type, and (d) high straight type................................................................................28

Page 8: CdZnTe - OSTI.GOV

I. Introduction

Cdi.xZnxTe *[*[#£ *| t+ ^ ^0j| #*| 7|^£| °|E7|7|, #

o| §§ m^sL\m ?|6HAi^ a|]o -a# ^£0|D|, 5 Ail^l^o^ 0|0j| C|j# g

tl7[- #^6| 0\ = 0\ X|EL oiCK £|£| oh^ §0]|Xi^ Cdo.96Zn0.o4Te2|- Cd0.9Zno.iTe°|

#^0| 7\™ °^o[ 510^ ohE^^ 0100^ #6| Cd0.96Zno.o4Te°| ^ infrared(IR)

focal plane array g#7|E[ #0| HgCdTe “|°|0| £i£|^ #-§-7|7|°| 7|#EE g

E| A[£E|EL 01 01 E-] °_h g#7|0j|^ ^ AH oh Zn E#2|- 7|#IL|- §

IJol Z>x|-§"[(LatticeMatching)# fl^o|~b £21##°! 7|#0| |E|-[l-2].

# MELAib #o| CZTE ##E|# Cd0.9Zno.iTeO|| E## ^0| 7|#6[ELA[ 6[

D1, ?|°| °|E7|7|, M°12AH 7171 #0|| ^A||0|Eh

CZT# 1960^C||0|| 7H^E|°ioDjj £|#01|# ^^7|#, 7[#

5H y^ia| 7|#^oi 0[L|Eh ^(Furnace) #7|| 7|#, HIU(Modeling) #E|

CZT Algol ^go[EL °l# fA1|0|Eh

CZT 7|gl°| 2#7|# ulHH ^(Band Gap), ## #A[ gA, ELE|EL £

#2| 7|-A|D|, 0|^ ojoH Ge(germanium), Si(Silicon) 7|gl°| g

#7|^g 0^L| E|- #m\2\ 7|gE| X-ray, y-ray 7|#E l=HA-||6pL °i

K[3], CZT 7|gl°| SS7|b □ o1-A)|0|| H|6H ## Oj|L]X| Al|#6p| [[fl#

0||[4-5], ^m\ 7|y SW7|0||A1 inO|£E C||H| A|^W|## #0|7| £pH A[§oK

photomultiplier tube ## A[## #fl7[ °JC|-. £E°h Ge, Si°| y^A]| @#7|# ^E.

7tS 0|| L| A| 7\ At0[ At^ojix-i ^ # # #-^-(Leakage Current)# L[E[L||7| [[|#0|| ^

*1£01|A1 A[§E|0|0[ op|D_l[5], CZT @#7|# #£0\\M 4#0| 7[#6p[.

1

Page 9: CdZnTe - OSTI.GOV

II. Properties of CZT Crystals

CZTOtl 4= Ke H^, ^^0j| °Uj CZT°| 7|£

^21 0|6H6^ %0| #s6p^ 51S # 4 °ich #o| &E[]i(phase

Diagram), A|-Gj--#-E|^ ZLE|TL y 7|5j compensation 0]| Ef] ol 0|o[]-^ 0|

1. Phase Diagram

Al^E^ojix-i [[^ ^“7_ho| AtAi|^|

^§^3 A|^ej LH0||Ai ^o]*! 2^(x), ^a(P), ££(T)0|| i=H°H 44°l

LhE^Hb 5!0|Eh ZLEjHfEl op I ?|6HAlb 2^

0| ^01^# Hfl 2LXi o_HXi 7|X)| &E[] m #Ej^ AtE[]io| 0|o^ 1^0|

E|-[6]. CZT°| ^ EH^Oll EHoHAi-b Greenberg? ^ U| JH^ §S[o[ A)gtgEt

(Stoichiometic) ?l °l #S# 1H A|^E) 7|#6^#

1100 -—

■ Te side1000 -

900-

800 -

700-

600 -

500 -

49.99 50.00

Figure 1. T-x projections of the Cdo.9Zno.1Te solidus [7 ]

Figure !-£=- T-x projections^. CdZnTe ■§■■§■ 0- congruent °lO]|Xj-p o|-X|

2

Page 10: CdZnTe - OSTI.GOV

&hggg g# MOjgp. Liquidus lineg !g#°| g# g^g# ^g0]|

congruent ggg 5*j0j|Aj g^gM# PgLHg. 0|Ej°l E||0|EjSgEj g# g

$ig ME[ ggg gMg S|CH£| Sgg 860°CO]| Aj Te°| S|C(| SX|| g

6j|S(Solid solubility) 4xl018 cm"3# 7|-X|S, Te-rich ^SS ^^°[E)-g gO|E|-. 0|E-]

g goj|S°| §§^ME) ^g gS01|Aj SX|| CZTLHOll Te

precipitationO| ^golgg gO|HS[8], !g gg gg# Aj|# [L| 0|# g ggg

OjO^ oiEh

Te vaporE) Te-rich JH-g-X)|(Solid Solution) 7\ 1 g g" EH g P-T projections^. gEj gOjg £g£| §EK)j| C|j6[| Hti oh(Partial pressure)01 gSOj| E|g°lgg #sol g# g SM[9]. oisjg gMg !g gg 7|# g gg ggo]| ang gggg.

Dp| °|SS, ig ^EHS[10]g Cd-Zn-Te ## g^| A| 0|gg, g^g 7|^S

A^g# g $ig gO]g gS gE| Cd, Zn, Te gE| ™gOj| [|jg #Sg Xj|

ggEK

S°tgg, Cdo.9Zno.iTe£| gEflS

0|S XHg^oig #g gg gg g^l #Sg gM# Xj|ggg %0\Z[.

!g gg# 0|g|gg 0|-L| EK gggt -a-°|g ggg gg ig gg# °A

2. Chemical and Physical Properties

g o'Oj|Ajg gg gg #g# g^opl g|oH SEjElOjOt o|-g CZTE| gglg

ei $^tg, #EM gg# 7|#6nsxn gp.

2.1. structural Properties

Atomic number: SOj|pA| gA^gg g#7|0j| CZT* AngggE|| oioj ggo| g

gg 7|g£| gg7| dhX|]S gEjg Silicon(Z=14), Germanuim(Z=32)0j| ti|6j| #g

15 lXn9S(Z=50)0|Eh

Density: CZTg Ef 6 g/ccE| ^S# ggE|-[ll-l2]. #g gSg y-rayE) gg #g

Ot|L-jX|o| HtA^gOl ojA^l [t|, #g Stopping power# L|- E|- E|-. A|#7?p| MSg

CZTE| gSg 5.8-6.68 g/ccS gOp^ °iSg[5,13], 0|Ejg ggg gA^g gAf- gEf- gg gXf- Ap|o| g^gg# #7pp^ #g g# £## PEPH^I Elg.

3

Page 11: CdZnTe - OSTI.GOV

Mechanical properties: CdTe -p-2i0]| Zn# ^X(7( 5)^1#

Cf[8], Zn-Te£| O|#i(iconicity)# Cd-Te°| 0|#^Mp *(°L( Zn-Te°| ##Oj|LjZ|

# #7| #1-§£]I1|' shear modulus# #7|-6|-EL, #510]| dislocation^^

01 It o (Sub grai n)£| ^^##[6]. Zn# *7(°fa^1

Oil Ifioi 0]| L] X| 7f- #7(6^| ##[14]. 5#, Zhang ## CZT0||Ai (111) #g#0|

7^ ## 51# 51# ^joi^EKlS].

2.2. Thermal Properties

Heat of fusion: CZT #•£] Z|°| ## #£]# CZT£| -g-o^ #(Heat of Fusion)0|| A] 7|

#°1#. 0| 51# Of 209.2J/gO|Dl, ^§0]| y§£|0]0f °1#[13],

Heat capacity: 1#^# CZT A| ### ## #

^0|E(. ## ^EH01|Ai CZT£| 1#^# 0.187J/gKO| U|, ELA||&EH01| A]# 0|M# #

20% §E ## 0.16 J/gKB^ #E]A| °[#[13].

Thermal conductivity: CZT°| l^EE^ ^X||&EH(1.085~1.09 W/mK)0]|Ai M# EL

XII o’EH 01| A( (0.907-0.97 W/mK) # ## 51# 51##[13,16]. 0| 51## # # CdTe

0)1 Aj o| 51(ELX||: 1.5 W/mK, °H X||; 3 W/mK)M# ##[17].

## ## #^(Viscosity)(4.15xlO-3cm2/s)[13]o^ #&H CZT ##°|

Prandtl number# °f 0.4 §£7f # #. 0|5[# CZT# ## ^E||0||A| ##0|7| M#

# y^X)| #^# ##t«## 51# £|#°f#. 5# #^# SiLf GaAs£f ## #

# #^X]| ##m# 1# # ### 51# # 4 $i#.

2.3. Electrical Properties

Band-gap energy: CZT# band gap 0j|LjX|7f #"#0|| A| 1.5eV 0|#-# 51# wide-

band-gap *f#0|Ef[5,18], CdTe# # 1.54eV£| 7^ 7fA|Dl[19], Cd0.9Zn0.iTe#

1.6-1.65eV£| ^ 0H#A|# 51##EL SfE=|*| °l#[8,ll].

ELXII g-EH01|Aj£| Zn #^0j| [[fEf ^£| 5£0| S#o[#E||[14], Zn£| *f^0|

#### Oil M A| 510| #0[X|7| [[|#01|, electron-hole pair# ^^6[7| #|oH #

0||L-|A|# °f#. X[##X[ #i# #E:6^| ##[20],

Electrical resistivity: #7|# # %[# #(1)H[ #0| fi## #.

1P q-(n-pn+p-pp) ^

4

Page 12: CdZnTe - OSTI.GOV

0] 7| 0]| A-] q=1.6xlO-19C, nUf- p# 7A7A electron!^ holeB| #EE |_l„, |JP# mobility01 Ef.

II-VI# y^*|| Al##Oj| U|oH CZTB| &## dark current# #7|X1b1

0 i# q a## %o\ci oie-]°i #^# a#7i mm ### ?\a

2L ohmic contact# ## 4" #El[2].

Ionic character: E-VI# A1##B| 5>h#l 0|#A1 #^# # 7|-X| #D|.h1# llBlS

°l^Eh CZTB| ## 0|#£1 #^# ##B| % 7|-X| #Bl# Op\a[Z[[6].

a. 2L*||&EH0l|Ai°| #H#

b. hexagonal #3:Bl twinO]| E||#l ^ ot^

c. stacking fault, dislocation^^ ## ##0| vacancy# lEJ"-E#E-|| #_Q_# 0|| L|X|

□1*|# #^# II-VI# ###B| #X1|0|E4 0|^ ojoH 1§# o'o^l7|7[-

□H# ^o\A- CZTBI 0|##- £*f# ## E-VI# ###MEl ### 51# g#

°H0^ o1E1[6],

2.4. Melt Properties

CZT melting point: CZTB| ###i# ^§0|| D||° #^61#. #i#

til #lJ#i, ^ ^°PI ?|oHai# yxi ^siot

§§^Bf 01# 5[0| ###0|El. Guskov ## Cdo.9Zno.1TeB! #### # 1104°C

E|-BL M2L6!»IE![21]. Shcherbak# 1112°CBl 1121°C0||Ai #^(n)# #iB|

5:^I"o|"m—°1, °IS cluster dissolving 7|#.h1 # § o|-E|-[22], EE# ### #o °ll

# tHAH## 1091 °C0]|A-j A|*[E|2L #EL# 1091°CO||A1 #### 51# “jo^Ho^

7l#m ## ##B| JH#0| 1126°CE1BL o^#. 0|# 71## #H# 0| #i0||Al

# ##6M ### 51# B|D|#E1.

Segregation coefficient: CdTe0j| Aj ZnB| segregation coefficient 5t(k)# 1.16-1.35 Al

0|^ MELE|EL oiEl[6,ll], CZTLHB| #^#0|| E^AI segregation coefficient#

0|| El El Els# 1ME1 ## #2L(In=0.07, Cu=0.05, Ag=0.05, Bi=0.02, Na=0.001),

# 4^ #E1(A1=3.6).

Strain: CZT0||Ai strain# ^^^|#0||AiB| ## # #W|1, ingot4B| Zn

B|oH ### # °AEh ^ Strain# Zn segregationB] ^$l0j| El El ### # ##!.

5

Page 13: CdZnTe - OSTI.GOV

D^IQJo^ §2iE|b # strainO| E|D|, 0|b £

% °0j| #°1SM gl## ^S °iE|-[6,23]. CZT-b critical resolved shear stress(CRSS)

&o| dh° 5[7| uncoil czt 1* y^onxi strain# nfl# SM71 Ig.

3. Compensation Problem

# %0\\M^ CZTOfl A-] g7M compensation0]| #lg# 0|#2|- °PH @f##0]|

>=H7|S°^h

3.1 Overview

CZT 1*# ^X-HlotS iot^EL oi^

( ~1016cm'3). 01E-] °1 #°lgol go)-### 0p|6|-# H# carrier drift length

# 1# Xi Xiot ^1# g#^. 2L Xi°t ^1# Qt i016cm-3 #S°| shallow

acceptors! compensation gSMAj g 0]# 4" °aE|-[24].

°ip°i gg# gg## o\^o[o\ *?m°\ #### #e#o|pm\ ### 2101 Eh 0| gg# A^g XH^o| y7|Xioto| WHS 1

§g ^-°|0j| Fermi level# ZCLggSMA&l 2i a# g. 0| [[| shallow-, deep-level ##

# Ap|01|Xi dopant°| g# ggggl S#g|0|: gg[25].

3.2 Native defects or residual acceptors

Cd vacancy(Vcd)# CZTO]| g 10ncm'3°| g-SM #g $1# A|-Xj| shallow

acceptor(sA) lgO| g[8]. 0| Ig# CZTOj|X-j g7|g MgHH carrier trappingOj] §

fiol q|f ohE|-[26]. g|g7f- Vcd0| Incd, ClTe #°| shallow donor(sD)g lg# T|

*[#, A-center# gggg. S Xig°| CZT°| g# Zn gX|-# Cd siteOj| #0]#aS

g VCd°| gM# gg. Figure 2# Mg IggSM Cdi.xZnxTeO||Ai L[E\L[

■b am 1#, ###, g# #oj| eh el o|6H# g 4 gg.

6

Page 14: CdZnTe - OSTI.GOV

Name cf erects impurities complexes 4_ .

£(j=0,01 eV— E- = 0.34eV Donore

---- £i+<+ =0.59 6V mca- cha Er-O.SeV

' cd

A centers

^CD-lnCd

£„- 1.572 eV for x=0,1

Acceptors^_/5__g2^gy Ea=-.j 0" — 0-35eV ^CcT^hfi£^-=0.13 eV ----- Ec/-=0.12-0.1 5eV

4

Figure 2. Brief description of the native defects, impurities, and defect complexes, which were detected in semi-insulating Cdi_xZnxTe with the value of their ionization energy levels[8].

3.3. Electrical Compensation in CZT

CZT01|A1 *171compensation ^2 7|## E|-## A1|7|-X| 0|E|-.

Compensation of shallow acceptors(sAs) with shallow donors(sDs): conduction band 0|-Ef|

# band emission# 7(-X|ZL ## sDs# EA# (Al, Ga, In)CdL[- VEA#(C1, Br, The-sl#

E] o o^l #[24,27], sDs# A center# ^#6[7| ##| sAL[ Vcd# ###E[[26,28],

A[# A center# #2 #2# X[A]| ### ###0]| ### ##. ZLX]°i

##01|Ai A center# EE]6[7|0]|# Ev+0.15eV2 #E[[19],

Valence band# Oj| X| o[# shallow acceptor# I A# (Li, Na, K)Cd# I B# (Cu, Ag,

Au)cd# 2#°[E[[24,29], InO| sD2 A[## [[|, Vcd-2(sAs)# E[## AjO]| #6||

compensation# E[.

In + Vcd 2 = Incd+ + 3e (2)

Ct| 71 A-j InCd # 01### shallow donor0| E[[30], Shallow donor# #X] shallow

acceptor# VCd"2# ##"o|-0j acceptor complex# [InCd+VCd"2]"S o o##. E[# ##|

2 deep-level# ## complex [2InCd+Vcd’2]°7[ ^##E(. Ct|71Aj acceptor complex#

## # complex7[ CZT0j|Xj compensation 2## L[E[## #0| E[.

CZT compensationO]| Cf|#l 27| ### Cl, In# ## shallow donor# 0|-g-o[

###, 0| ZL Ajgj-# CZT# ##7| #of| 2.### donor-acceptor ## 1

7

Page 15: CdZnTe - OSTI.GOV

# 1 compensation# #7|7)- °j#E|-. E# #-§ ## al|"o01l/M segregation

coefficient7f- #*| IPPPI [[H#0)| ### l§0||Ai ## ###

compensationO| #0]Lp|E #E|-. Shallow donor# #EE #£-)|0]| # A] # ppmS|

-SSj-EE shallow acceptorO]| S|6[) -§S[o| compensations!0)0): o|-#Dj|, 0|# □)] °. 0]

## ##0|#.

Cl01 L|- In# E# °l"Oj S-H)--# complex: (Clxe -Nacd )°, (Vcd 2-Clxe)-s

o o acceptors! ###S^ Vcd°| #E0|E|-[24].

Compensation mechanism by intrinsic defects: intrinsic defects0!| S| # compensation#

Vcd’2Sl- Te anti site #1° | #iZ#'-§-01| S|#°lE|-. 0| compensation ### A|-§-o|-#E!|

##S| ### ##7|S| #X1| H7|7f- #E, compensation E|X| ## defect7^ ##

##7|S| ### A] of- A|# # °i## 01 E|-[31].

Compensation with deep donors: deep donor# 0|-g-#l compensation# shallow donor

# 0|##1 # # M E)- °l#o|-E|-. 2| Lp)-1# AjgJ-# deep donorS)- shallow donorS| #E

o| otojl |% ot#0|7| [[|#0|EK24].

#7|# compensation# ^E #S| ### # Ev+0.8/0.74eV #AjS| ## #X)-

leve!0)| ### ### E#gJ-EEM.-| ## # °i#[19], Deep donor# #1 # $i#

intrinsic defect# GaAs E#0)| Up!- Te antisite(Tecd)E W^A] $i#[24], CZT01|Ai E

Aj %-# E# TeE #6)) tiHE. # §ol"-#°l0ll pinning# Fermi level0!| Teed s#S| #

4 ##[19,32].

Deep level ### #7|# compensation# #7| #o(! donor E§# ##6[)

Op|##. ## -oj| §Eho| E## ^##EEA1, n-type 5# p-typeS|

conductivity# ## # ##. 0]|# ## Te-rich E##OHA]S| ### ###

EE p-type conductivity# #E[t!!E|-. 01E]#! #■§# #^#EE TeCd anti-site(deep

donor), Cd-vacancy(shallow acceptor), Te-related native defects)- ## ### E#o[E

#E[[8,24,31], Deep levels) #E7[ 1013cm"3# ES[o|-#, deep electronic level 0)|

# ## #°[(space charge)7)■ ##aS[# ### ^ 0|E ##| ##7| L||

S| #7|## y<g]A|7|E, ## charge collection efficiency# ## ### #

°ac[[33]. A[#, #7|# compensations)- E A-j°J-# #7| #6)) A[#E|# -§-## deep

level ### # H £j" # E# carriertrapS) ### #|jj#-E|-[34].

E A]&1# #otol E§ ### A[-g-o|-Oj #01##. Dopant# ### 1##

8

Page 16: CdZnTe - OSTI.GOV

-b 5 WO I aa—°1, compensations] B B 7| level-B intrinsic deep level 0| b|0|-[24]. Sn,

Ge, V-B CZT01|A.-j deep donor si A(-§-E|Q^, V21 Ge°| deep level-B midgap(0.75eV)Sl

7-| °| td|Bop| HUB °11 photorefractive #0]| -g-"oB W- °I5!"EB- deep donor0j| £|W

shallow acceptor£| compensation 7|B# WBW. Pb, Sn, ClSl dopant-b o'£-011

ll\E\ n-type EE-b p-type AjWS W# B $iW[28].

9

Page 17: CdZnTe - OSTI.GOV

HI. Crystal Growth

CZT£| #E|, ### ### CZT£| C|]## ## ## #3# 0] E[

°l #EEX|| ^#51^ ##£|- td|U!5H cm 4 M ohck # X[

01#]# ## y&0j| gg# #A1|£[ ##0|| Hfl# £7| ^##0|| EH A] 7|#°1

Ch EE# ## ## A|#E]|0|# #£[, ^ 7p| ## ## ZLE|£L

#0j| ^## C[£# #ot^ #§6[£LX[ #C[. ## O «A|a|o]| #i6[o|^. #g#c[.

1. General Problems and Initial Conditions

CZT !# #&0|| otAi £LE]£|0]Of: # - 7[X| #E2 0|#7[ °IC[. % M, 2LX||

#E||£| «#^7[ ## ^EH0||Ai £E[ #h£[# 510ICII 0|# #21 #l(Latent Heat

of Solidification)01 £M| 2h^£|X| °4# £|EI|#C|-. 0|^ ojoH #£L A| oH#-£L

# ^|@(SLI)£| i#0| #0|A| ^# #4# £*\P\ ^##£[[35]. # M# ##

^CH|Ai CZT£| #^0| Cd£| A|##o| ### 0p|6[# U|#^#(noncongruent)0|

2-H= %0\Z\. #2hX|| ##0||A-| Cd£| ### ### Te-rich ##£L, ###

0j| Vcd"2£| shallow acceptor# 0p|#£[[24,36], [[[E[A] 0|E]# ### # ^#6[|0[

##E]|, ZL1X| °4# go Vcd"2^ ### !#£| ##0| X]|#l %

0|C[.

°|o| ^ 7[X| ### twin, grain boundary, precipitation, Cd EE# Te inclusion, #-§-

^0[| £|# crack, Zn segregationO]| £|# 2i# ### ## 5E#6[Q| ### #-§

#X]|0[| #*] 1# AH## 0[7|#£[. EE# #### 1#°| ##

1#0| ### # oiC[.

1.1. Starting Materials and Stoichiometry

2|#0[|# CZT 1# ### ?|# #4hXH 7N°| Cd, Zn, Te# ^E# ##0|

5iX|#, 6N£| 4hX|]# A[##£[[12,37], ### ?PH °H#(ampule)

0|| #2J6p| #011 #2bX||# X]|#o[# C[otof #g0| oi£[. 0||# ##, Cd# H#

###0|L[ ^@### X]|7]o[7| <jH methanol 7|#£| 15o/o HN03 §°-«££ #A]|

#£|-. Zn# HN03, H20, HF# 1:10:2£| td|#^ ## #°!|0|| A]|#6[0], Te# 20% HC1

#°Ho^ AhA]| #, H20^ ^J#£L £L#i£| N2 gas^ #^A|7] A]|$j# # oiE[[5]

?|6HA|# #2hX||£| ##£| H7|0|| CE[E[ C[2

L[ 25 mm A|#£| £f 300 g ■§iO|E[[35].

Page 18: CdZnTe - OSTI.GOV

CZT°| 13 b 133H. M Cd, Zn, Te #33b# in-situ synthesisM 3334

[33,36,38], Cd2[ Te°| 3#0| ^«^H[ $|130| D||°. H7| [L|^0]| 13 A| #M

5## 333 # ^moHO[ o[C[[33].

1333 51# 4°H 351 l#o]| ao]0[ # #7[##o]| 31 oho|

b uaA| 1, #HMM Te-rich #30| #130|| deep-donor #4# 1#5, Cd°|

#34# 3bbqi A[#gc[. ygo]| Cd-rich #3# 13 33 #4 #1 4^011

A1 bll# Cd# M3°P| 4°H 0|##c[.

3E. 14 #40]| deep donorM# Tecd°l aE[# ELE]6[1 Te-rich #3# EL X]

34 CZT# ^7| 3°^ MELE|EL 43[39], 4 1~1.5%£| #7[ TeO|

3 bbH- ZLE] L[ Te-rich #3# 5j§f 3b Te inclusion0| L[ precipitation°| #

M7[ #7[6[# 130| °IC[[25,34]. #EL 2[3 # b^Oj|A] Cd£| #1 [[|#0]| Te

inclusion01 L[ Tecd 134 #M7[ 33 31# 44 H #7[6[# 310| 43 [25].

#EL # bll# Cd# M^opl 4°H #4h40]| Cd# #7[ # 4 $ib4 0|#

33 # 7[5 3EH^ 3#4 333 ### n#4 33- ciapeyron A]0|| °|o[] 4

3b Cd°| #7[ 4# 4 0.05% lMO|E[[40].

Cd #1# M3 op | 43 MC[ 3JH3 34b cd reservoir# #11 MM 51

3 4 4b 2*[ furnace0]| 34b 33 3#o|| 4333b #0|E[[41]. 33 51

0|| CE[E[ C[2L[ 2A[ furnace®.| #M# °[ 785°C §EE °X|#C[[42]. 0|E]1 34

# 3#o[7| 4°H3b 33 bE# 51# b 4b 27| 5# 37| 0|3£| zoneM

M 333 furnace# 0|#6[|0[ #C[. A|5Ej0||Ai Cd# M3°P| 43 Cd£| ELI 3

b 1-1.3 atm A[0| 0| D][33], 44 5:3## A[## 3b dislocationO| L[ Te inclusion

# 443°5 #4 b 43[33,41], ^|C[7[ Cd 3#0| 0[y #3 mole ratio(Cd/Zn)

4 #3# reservoirO]| 3#o[7|M !□[. 0| 34# #31 Cdi„xZnxTe0]|A] #33 x

4 3# 3# b 45# #3[6], Reservoir4 bE# 820°CM #113 bA|E|7|M

o[EL, 800~840°C A[0|0||A-| #*[#MM go[7|M #C[. 333 134 #53 #1 0|L[ 37|A]3 7h# reservoirO]| ##1 Cdl 4# ^M# CdZn alloy7[ 4# ^

333 3[43],

1.2. Dopants

Indium# 1010 Qcm®| A]33# 7[A|# p-type #1# 37| 4°H MllMM A[

#E|# JE™ #10|D][35,44], 3 1.5-30 ppm(1016~io17at.cm-3)4 #MM JE# 33-

Page 19: CdZnTe - OSTI.GOV

In°| °f# ##. 30 ppm®| In *1#&# 1011 Q

cm#X| #7p|7|# 60 ppm 0|#°| n-type®| A^## CZT# #

#7| tL|^0|EK44].

1.3. High Resistivity

£1# shallow acceptor (Vcd) deep donor(TeCd) M#0j| [[(-.eLS, ## Aj##

czT# ^### # 6[L[k vcd# M^op| $mx-\ InHf- ##

shallow donor # 0|-L|Ef- Tecd anti site# #A|0j| ^#6)-# ^0|E|-. A|#77|-X| 7\% #

# 1^# 1.5%®| Te %7\9.\ 2.5xl016 cm"3®! In i§# °H# 0|# £

S E|A| g# CZT01I ti|5H 1000HH 0|# otxtEi ^h^0|EK45].

1.4. Zn concentration

CdTe 7|Z|0j|Aj Zn°| segregation coefficient^!- lM# H7| [[(!#-0j| CZT # -§ 0|| A]

axial, radial ## H#0!| A] Zn #_E -^p-tdHs o°MI S #. Segregation®! -§!£#■

Zn #i7f- 10%, 15%, 20%^ #7|-#0!| CE|-E^ 7j # #[1,20].

1.5. Superheating

%0\\k\ 0|7|°H#0| ###i e^01|Ai CZT®| # 0|## #&H ##

^EH0!|A1 Te #A[7[ A||#IL[ ## #i# # #. *|| ®! A|^@l#0]|

M ## 0[L|E[ D|*|# §°| 0[

7|1 4 $M6,46],

0|E]# °7|# §°;g 0|Ah0!|Al Te cluster# ^##TLA[ ®^ 3#0| ®l

#[35], ZLE]H^ #A[##2[ *|#(Complexes)# 77H5E|ffi, ##6|-ZL W|#^#®l

®J7| oHAi Superheating01 ##. ## ^o|| Te Xt-o| g##

LH0)| ARsl-# trapping center# -^##.2.51^1 #§®| ### #2hA|lJ # °i#[47],

0|E]# =X1|# 6H16p| ^|oH #A]| ## o^|A1®| ##, superheating# #

# o h°l ##5|7|^. ##. #A]| ERyS—-^--b accelerated crucible

rotation technique(ACRT), vibrational stirring, electro-magnetic stirring #0| $i.#[6].

Superheating# %% #0|| ®[# ##|# ### ##|W # °p| [1|#

0|| yal #### o"So|e|-[2]. 0|0!| eh# ### ##7[ ^ 7[A|

#fi## gE|6[g OpH# ##.

a. 20°C 01#®1 superheating# # 20~30°C -§_EE_°| supercooling# 0[7|o|-TL 0|.eL

Page 20: CdZnTe - OSTI.GOV

10 ingot°| 0E: 00X|0O|| 010 (Poly crystalline) 1.2.0 0[2],

b. Te cluster# E(-Il|6p| °\6Hk\# 20°C£| superheating0| lilo!0[24,35].

c. superheatingO]| £|# supercooling Te-rich, Cd-rich #1 5.#0|| A] Cd #

71! 01 %7\ ### 04h#0. EL 00 00 4^7( 07!#0[46].

d. supercooling# Cd 1X!°| li7( #### 0Ei#0. Cd £0!# Te X||l

# E|-2|6|-2L, short-order cluster 00# #00 7|#E||, 0| cluster# 0h

000 Oj|LjX|# 1#0[46],

21001, superheating# El# H-VI ^ 0##£| 10 00 #00 0#E|0O!

#0[28], HU #E1, superheating A|^lH|- ## 1 hi story 2) #0°| E!01## EL

Sl°| CZT 10# 1#E-|| 7(0 1# #0 00O|0[33,46],

1.6. Solid-liquid Interface

CZT ELX||°| U# uncoil #0 00 #10 EL0-00 ^|g(SLI)0 #

°I1 l£L7( °I0[6]. #ELE|# #1# 10 SLI£| 001S #0 00E|# 1#

100 ##. 7|#0B^ 01510 SLI£| 0EH0 #000 got# 0*|#E-||, 0|#

00# 1#1 ^1# #oH X1|0# 0 °IE(. SLI£| 100# 0° #2L#

Ei 0|# Zn #i£( 07| XiotThQl SLI£| #EH0 Up! ^Ep|7| [LH#0| 0[25], #

1# Zn #i# 0# 1#7|# 17| 000# ### SLI7! ##0O|0. 0|E)#

0|# 0#0 0#0 CZT #0 00 0°K>|| 0### SLI£| 0EH0|| 0# H10

0 A|#0O|#o| <207! #1# 0oHE|EL 00.

2. Modeling of the Growth

0#1 10 000 110aEi 100, 10, 101011 £|6H 0#E|# #0O|

0[34], CZT ###£| ##, 000 00# 00O||X1 EL #7|0 10, SLI£| 00,

°H0-EL0Ol|Ai£| 10ii, ELE|EL 0# Hi# 00 Hi A(0|£| 00 05>0#

0O1| 10# 1#0. 0| #0||A-| SLI£| 00# 0|j# #fi#EL, 0|0|| EH# 1#7(

#0E|EL 10.

110°^ SLI# ##0 ##00 °|0 0000EL 10X1 10. ELE|EL 00

!0£| concavity/convexity£! 10£| #0 0 #1#£| 0001 1#0 0| MELE|

ot0[48]. 0X1|^ SLI£| ##7! #0°| l|00 OH# #&# 1## 000.

10 0#a^£| concave 0 1 #Efl# ^|10 ##£| 05>0#O| 1#°^ #

Page 21: CdZnTe - OSTI.GOV

7\\ #.n|-E|EL, so LH#°1lT=r twin 01 Lf- dislocationO| C|-. #g0|| convex 7||

oEfl°| 3#01|# °£W ^0]|Xi >^E|# spurious #%# $\±s\ A|7|D|,

01 ^## #I§E|X| Sf^CK ^0||Ai ^E|EL

ttH^01| g^|gOj| EL*fE|# Te inclusion°| D^Eb convex 7\\ E ^ Efj C^| Ai #4i°l

^[48], fflEhoh ^|goi|Xib radial n||° Af# #£ #B||#0|

gXH^EL, axial “f°f°^# 2|°| ##op| [t||#0|| 0|#*]°^ |§a§ $\±s\ A|

7|EL, l^&El ### °f&A|7|D| inclusionE| Hi# $\±s\ o^E|| 7[%

^[48], 7\\Z[7[ MEhoi ^|g# «e^ go|EL, Zn°| radial segregation# Q\

Xl|ota^Ml grain #E-H01| °B|6ph

CZT oo1-—I A|#E||0|#0|| ## #^6| #°HE|2, oio^ ^ 7p|

a|-o)| [[^ A|#E||o|# <y#### 0hE||0|| §a|o^EK

Crucible effects: Graphite crucible# ## H#E_E_.5l #] ofj axial2^ radial o^cf—I #

£ fWH# #iA|7|#Cl|, 0|# furnace #B||# 0|i #]oH #X1| #i

# furnace 0|# #_EMI# HH|-# 4" aa^IT7]- Graphite# quartz L||#0||

A1 ti|## S2[f od# - oiEh ^xi| #i# graphiteEl #^|0|| Upf-

°£W 0|# ^EMC[ HH^S #i, if #i OICK 5# axial &*f°l #i

SLI£| ^&# i## # 5i^[17]. ^#E| alignment# □«-?■ °t i°o| 7|

#0]#0| l§o| zj0| f|OW£| H|EH^]^# segregation# 0p|# ^ °i

□K49], X|X|E[|°| gotoji ffloHA-ji JHAl| mullite, ELX1| graphite, graphite

coreEf- ## €.[<£& ##, C^°h @#E|2M. X|X|E||# *\%o\ #^|#

axial ^*f£| 1 A## #7p|7|EL #A|0|| radial ^*f£| « ###

A|g # °M50], graphite^ PBN crucibleO| CZT A|0|| Af-

#E|#E||, figure 30||Ai MO|X|#0| # Af0|0||# #i profile X[0\7[ #XH^# %

# # 4 °icK51].

Furnace effects: ## Bridgman •£j£>hO||A|, tiUl"-E 0|##i# unseed A|ig|0|| A| grain selectivity# #7p|#c|-. #A||5. Zn£| axial segregation# -£j£f #JE7f- HH|-# HD #EholEK52], #§y# ## ##i# furnace£| #i profileO|| §°f# “># □K13]. EE°h SLI# furnace£| 7^A|^gjO|| g°f# “>7| [[|#0|| «5| #^# #

convex ^|g# ##A|7|7lp ^Af|# # Pt tube# °§#£| A|A|E||^ A|"#o|-# EfS #0| oich s# #|fo| « #S# #EhA|7|7| E|#0|| Af-7|&# #0|#7|i o1eK53],

Page 22: CdZnTe - OSTI.GOV

G1—G4

P1-P4

J I L J I L J I L J I L

Normalized tempera:ure (K)

Figure 3. Axial temperature profile versus height for graphite(G) and PBN(P) crucibles at different growth stages(Gl-G4 and P1-P4) [51]

Experimental condition: #_E. ##4!# SLI# Ef] 0]| A| 7[A]

4 SW, spurious 0[7|# ^ °M34], ###0||A-| #H|]°|

## q #&6[c[ 2|L[6[g

SLI°| ^ EH0]| EH oh [[|] = 0|E[[13], ZLB|ZL ^ crucible pulling rate#

1 ### SLI£| ### 7|##H[ #A|0]| so o'01| A] ##

segregation# A]|7]# 4" Si#. MEL# ### 3:#-# 0.7 mm/h# 5°C/cmO| E[[16]

3. Methods of Growth

# O1"Oll^i-b CZT #-§# ##Z|7|# ys #, Bridgman method(BR), vertical

gradient freeze(VGF), traveling heater method(THM) 0]| E[]6[]A] 7|#o[D]5 #o| 21##

£| CZT 1## £7| 41# ## ^#0j| #hoH #§o[£LA[ #C[.

3.1 Bridgman

Geometry, preparation, composition ampoule: ## # Cd #shH[ ### #

## HtA|o[7| #°H °-!jX]| LH0]|Ai ###E[[5], Seeding ### 7|#o[7| #°H

U seeding tip01 ##E|7|^ #E[[24],

1 5

0|IU U

Page 23: CdZnTe - OSTI.GOV

°£WB ### 7[# agg quartz, graphite, PEN #0| A[#£|#E||, 7[# ag#

quartz# A[#6[# E[# X||## # [[flMEf- #§#£1 dislocation 1Ji7[ # #°| 0|

At #0[#E[[24]. Graphite# # ^#0||# ## 1^£££ ##| axial/radial ##°|

#H||7[ # ## ^0| ##£|#E[[24], ^|E[7[ !§## #0|| #7[^#

oHOf: 6[# #A]|^ ##. Graphite°| ### quartz #0|| U| oH U| JH^ ^@^7[ # E[

# #0| E[. Oxygen°| shallow acceptor5. A|##A|#, carbon£| ZL# A|

&hE|-[39], Quartz °§#£| ^fi# #£## Na, Li# ## p-type #£#^ p-type£|

so# #-B#. ## PEN crucible£| crucible0]|A] 7|°lo|-# Z:#£| boron£.5.

p-type, n-type CZT# ##A|# ^ ##[31].

Boric oxide encapsulated vertical BR# #tt| L[jOj| °[ 5—10 atm£| Ar gas

# *H# open OH## A[##E[. 0|# tM| A1|7]£|# °f 100-150 pm£|

# boron oxide## 7[# ## A|# ^ °(E[. 0| #### o"#£| L^#

1§°I #E]## ## ##°£El# 7|^|## #a# ## 4 ##• ZLE]£LfEl #EE

# ##0| #At£|ZL, dislocation 1Ji7[ #Oj^E|-[54].

□ # A|A|C(|^ cold finger ### ## Pt tube# A[-g-o|-7|_E. o[#E||, axial heat

flow# ##o|-ZL, radial heat flow£|- ## #JE# ##A| # E|-. EE# ## ##0|| IL\

B Zn #££| #### 7|##E[[55], Figure 4# A]| 7|°| <gg[||# ### Pt

flnger£| ### MO]##.

Configuration and modification of the Bridgman equipment: Bridgman furnace£|

single zone, two zones[15], adiabatic zone, 1200°C£| hot zone, 980°C£| cold zoneEEiEL #

## three zone[43], five-zone furnace[32] # E[#o[7|| ##£|ZL #E[.

ZL# BR# CZT£| ^#0J| ## #0| 0|#£|# ^^0\D\,

Te-rich i# #0||A-| ##A| # E[[31], 0| # 100-120 atm 5# ZL 0|Ato|

Ar -nr°|7|0]|A| # # 6[ O], graphite cruciblell^ graphite heater# A[##E[. ### #-§

#°| #### A]## ##£^01|Ai Cd ### $\±s\ A|#°^# ####[39],

Zn ^#£| ##### ### #A||0|| #Ai Qt 5~10% §£0|D|, #L[o| ^

#7| 7|#°^# Qt i_2% §£0| #[39,56], ##7| ##°| j||S # 25%*

i0|#.

ACRT **|7[ ##°| ###A|7|7| ##|A| *#£|7|i ##[20].

Page 24: CdZnTe - OSTI.GOV

i— 50

IU:i!3

I <£o<3

C JZn: ^ 2

E 1A

A

<1

<-1

<

. ^

-8

L (an)

Ft tubs Heats1

Aumlna wool/Thermocouple

--£0

--F5

I--40

Figure 4. Bridgman method with the Pt support, which acts as a cold finger during the growth of bulk CZT crystal

Experimental condition: pulling rate(0| 0.5 mm/h O|o[[5,35], 0.8 ~ lmm/h

[36], SE-b l~2mm/h[57] # #2[#0| MELE|EL °[C[. SLl0j|A]E| f

# 10°C/cm 0|o[[5], 10~15°C/cm[57], 15~20°C/cm[43] #E| 12[7[ MELE|EL °[C[.

□ [A|°|°^ O At^77[X|o| LH7t 4^# 5~6°C/h°| #i7[ A[#

£!F[[43],

3.2 Vertical Gradient Freeze

BR yg0]|Aib furnace7[ Z|A[ #^0|7| [[|^0]| ^7^#

#3^# S[M6[7|7[ Ojac[. a 1E[ fumace°| #i#H|]7[ ^§o[E]E[EL ^A[^

o| aygo| A|^A]a^ #3°! !Jam. ne]L[

VGF ygOllAib 01 E] °1 ## 4 °icK

VGF yg0]|Aib °£W yX]|o| oj5[^ #£ profile# °1#7| £|t>|| ^ 7|°| heater

7[ 4#^^. heater# EL§E|0] °(EL, profile# 0[E^ ### #0[A|

7| [L|#0]| SLI# #^0|gA] ^^olE[[42], 0| =

7| ?|oHA1# #£ profile0]|A] A|#A]o| @E[# ##0] ## %0|C[[33].

Page 25: CdZnTe - OSTI.GOV

VGF£f tdI^oh g7|4EE 4#0] electro dynamic

gradient (EDG) 4td0l Si—LK #E 3: a# °I°HA|# LSh°l heater7f

Sfi^Ph 0| 4S# 4^4 A|7|EL supercooling# 4444 44 4#

1 444 44 #E# 4#4ee4 vgfo]| H|oH 1^1 AAA «

444# 4# 4 SM58], 10% ZnE #E4# 4444 4EE x\X]\

0j| #*| °f 5~13%£| Zn E40| LfEftKf[8].

VGF experimental condition: Ef°fo_l crucible ##0| A|-g-E| #44EE PBN[31],

pyrolytic graphite 7 f ELUtE! graphite, graphite 7 f ELUtE! quartz 7 f Afg-£! Ef[59], 4 785°C

0j| Aj 1-1.3 atm 4^=14 Cd reservoir 7 f 4#44-E °lEf[42]. Axial #_E. #b||# 4

l~5°C/cm4 3~10°C/cmO]| 44 lEpf MELE|EL Si4 444# #44 SLI£| ^

A #E# A 0.1~0.5°C/h EE-b l°C/h°| #4 #0| MELE|SlEf[42].

3.3. Traveling Heater Method

THM o'S01|A] #CH7| SLI£| 44## #^A|4°^4 44 4# L||0|| °HAt

44# 4#2l #A|0j| l^otAj #!0]X| E4# 4#44 0p|j#0j| #4

4# °| A| A| 4 E|-[3]. THM yg£| 44# BR0| Lf- VGF0j| U | oH #E01|A1 4

4# 4 Si 4# %0\A. 0| yg# 0|#6f0j 444 #44# Of 4~5 mm/day #

JEE 444E, BR0|Lf VCF-EiiL X1|E£| #44^4 Oft+ #444 Zn #E°|

#44# LfEftHEf[60]. 7j|Ef7f heater# #44# 440j|A-| ####0| 44o| j\\

7iE|7| ttH^0|| E||l£| #### LfEftHEf. 444 °Ueo| U[X\A

#EL ^0]|Xi macro defect 7 f LfEfLf7| [[|#0]| Cf| #4£| #44# ^7|7f ##

Ef[42,60], 44 444 4 EH# #^4 q|=£f 444 #&H 44 444A1 #0]Lf

# 14 44 444 ### 47| uncoil sli# ^#444 0^4. thm 4hl3#

#44°^ solventsAi Te 5# Te-rich dilute binary 4### 0|#o_lE|-[60,61].

Experimental condition: solvent zone£| #E_# 4 850°C -§E0| D\ [53], Te inclusion#

*114 4^ SLl0t|Al£| ^At ^444# #0p| Xp|4# 4#A|g - Si4-

7f4 444 44 4444 4# A 3TE MELE|EL Si4[53], ™™4 SLI# °§#4 Wfcnggoj ayg ^yo| ££f2f « XipH E#, °H#£| 44# #°H 1# 4

Si4[61]. THM0]|A]-g- seed #440| #&4E, 44 4E# °t 4 ^5

mm/dO| E|-[42].

3.4. Other Methods

Multitube physical vapor transport(MTPVT): figure 50j| Aj MO]X|#0| furnace

Page 26: CdZnTe - OSTI.GOV

oil #Ojy CdTe£[ ZnTe #g# 0\go[0\ quartz #Oj^j °l#

GaAs EE# Ge seed# 0|-g-6[Q] oo"#7|# o h °l E[. Vapor growth #EE#

ot 800°CO|D1, A|^EJ yxiib ### 4 2U# 2iy#01|

E|-. Axial/radial Zn i£0| ##o|-E|-# #I1[7[ MZLE| °p[[62],

Dewetted growth or growth under microgravity condition: 0| aoc>0|

crucible S^Hf- #B|*]a^ ##o[A| ^^6[# §oj gas ojao^ giJ0||

Ai hydrostatic £M# ^0|E[. on# H^IL[°| ##0]| °|°1 §a§ £|^£[A|

^ SIS WS## - 5i^[12],

Replenishing melt with Zn from a reservoir: 0| # ooh # so—I ^ oS #

A|Ap|#E|| ^^0\ °lEh E[# crucible# 0|#6[0] A|°H6[#E|| J= 7|°|

crucible# # HAi|#la^ g#6[0] £1#^ ^X\o[JL Zn°| #g# 7[#6p| #□[

[63]. 0| I o1" □# 4 atm°| Ar t°P|0]|A] B203.h1 encapsulation A| TjEEJil

A] S'## o"A| o[# 5[0|E[[43].

Farl flow

Figure 5. Details of the multi tube physical vapor transport[62]

Page 27: CdZnTe - OSTI.GOV

4. Growth Defects

£&£! 19^011 1#^ CZT 7|yo| g#7|®| ^0]| got

# □!£!£[. a#7| ^n[ y^o| 0|#o| !3&°l fi?!, ^EH^j

s^Oj| °|oH L|-E|-y-E|-. M. ^OjlA-]-^ macro-, micro-defect 5.-^# 5#o|-0j ^

CZT l^Otl \-[E\L[± ##0j| E[|6f|A| #gS[ELX[ °[C[.

4.1. Cracks

Cracky °H# LH«°| ^ 7|^M #aoj| o|^ agojj ^ ^ot o ^ A|*f

e|o] £&£! 1§°| y°HoiEh o | e] °i #ot^ ^^ #0|Lf. MQ o LH7t -0j| ah^e|EL A|°Hoi^. ^goi « profile^ crucible AH

1°| #°H crack °\*m -a- oiI AA E[. ZLE] Lf- slicing, dicing!^ £]#h

^0]|Ai ^°|# 7|#0|X| Sfog *7^0^ ^«0| -a- oiI AA E[. Cracky

@#71 ^## 10]EEE|2L, !3&o| 4## ^ S.o|0|Qh[2].

4.2. Voids and Pipes

H°fO|Lf- 7j|2f <gEf]o| voidL|- hollow tube ^EH°| pipe-^ 7\% #fi°l ##

#o| o |- L|- 01 E|-. 0| ###^ ^°fH[ ™°Hoi Hhoto^ T^THo^ L|-E|-L|-Qj 5

L^E^KK 0|# £i£[ ^iEf- #g

□ H[ Cd gas bubble®| trapping °| l|II|-.5l #E] A] %[E|-. 0|-^ 5E°_1 Te-rich #

#0|D], « profile, crucible X|]#, X]|0]# ^ °IE[[2].

4.3 Stress

y# macro defects ELE]E|Et], 0|b CZT #%®| g7|A], #^0j|

EI|AJE|-. §a^ #o| ##9^7]^ 1 #HH 5# oh#

^ 40|2| &°1 AtSxt§0]| o|6H ^AHot ^ oi^[48] « #a# ^3-

axial &*J£| ££ #b|]0|El], ^ M# #£| SLI°| ^^0|E^. <g #

q# #0|-b o^L^o| bjg§ on#2^ A[0]°| « sHAt %0|E^

[48].

L0]| o §a0| #AH# 4 $M- 0|- aHEb #a|A]2[ 7|^M 7[#

i7| AIM# °\ol #W_1A]0| #§0|A|®1, AloHot Hgo| ^^9^# 0[

7|o[0] 7H - r7|®| lOjEEl 4 °i'-[[64].

4.4. Twins

1§LHo| micro-twinOl gA|]# #2L °0]| f7[Aj®l #qO| A|^E|®tE^

Page 28: CdZnTe - OSTI.GOV

51# o|D|oh^[34]. twin# 04 #0 #£| #i #004 °|oH 00

#0. 01^10 AH 7|0||A1 0]# 7|o| ZL-o^ #0E|#4, CZT£| {111}S4 #0|oi

# twin plane# 44 0^44165], {111)0# 00 002) A 8°0i 7|#4A] °i

Cl. ##7|£| 0#4 twin01 0X|# 00# 4# 0 0 6)4, cooling profile# 000

iMM] micro-twin£| #X)# 5:11)4.2.51 fl y 210.

4.5. Grain and Grain Boundaries

## #i#40 HH10 00#i4 o|6H 00 -0|| 00E|# #0 40#

0.5%Br-MeOH 40 #°H0|4[66] tungsten 0#£| Egf O|-§-6)0[29] #0| 0#

# 4 2! ci.

Grain boundary L|| 0|| A] 0 #### # s®|-7]| #5EE|0 51 EL, grain boundary# ##

#0| 000.2.51 H0|# #0| 0 Cl[29], Micro-photoluminescence #2)# M0 0| E]

ol ##### donor-acceptor 4##£| 1.4eV£| “!£ 44^1# 0A)04. Qt 50 M

m 0_5E£| Te inclusion# grain boundary0]|A-j 4#E|4 0| 51# 0"A|°| 0## 0X|

44 10EE00[67]

#0 counting efficiency# A A—I 4 s grain L||0|| A] 000 A 21-2-4, grain

boundary71 #4# 0# 004 0M00# 5]# DH0 #&0 40001. Grain

boundary# Hi El# 1104# trapping a2)# ##110 04 00# 0#iM4 SW7|o| #0o| #6!A|0C![34]

4.6. Dislocations

401 dislocation Si# H0 40 40ii #04 0, etch pit density(EPD)£|

AA 0#O| 04. 0|E]°1 400 4M£| ### 0044 #4#Cl. Dislocation^ #40 ##7|°| 00# XiolA|7|04, #0 0#o| a|00 EPD

103~104/cm2°| 00 44 51014135].

Dislocation^ #0# 0*1 ##04 °|6H on# 40O||Ai #0# 0 51

4. 010 A|0O|| S40S 00# 71#MM4 4## # 21 Cl. 0 #214

00 # 0440 4 A] i2) S04 °I4 #0# 0 21 cl[34], 4x|4iM 00 i

001 #0 E|51# 044i S00C1141], Furnace 444 ## #i 44^ 04

dislocation# polygonalization EE# celluar tl|| ## #1121. Supercooling®] 0EE., crucible

o| #0O|4 0*| EE°1 dislocation Si4 00# 44# &0#O|C).

Te precipitationO| ## dislocation Si# 0# eh# on-1 00°|E)# 51# 0

Page 29: CdZnTe - OSTI.GOV

D|#E|-. s*1| Te precipitation# #A|| ## dislocation #5# £1-# o#°ll #Oj °(#. Dislocation# 555 precipitation °| #A|| #2]^] 'QTWeL S[oI'£!'^K68]

CZT crystal®.| ## EPD &0| #&6p| [[]]#0]| l°Jf in

WA|g - OI- 011*1 #@0| 7|#E|5 oiEh £ 7(A| #a°l 0]|*l#oH0]| F]]6f]A|

O^MI 7|##5Af-

Nakagawa: 0| 0j|*j #°!j# (lll)A Te plane®] EPD# ln#A| 7|#E|| 7[Q #0| 74

#E| D], etch pit# dislocation^^ # ### HF/H2O2/H2O.5L #-#£!□] volume

fractional 3:2:2# 3# 1#[28], 3:3:2# 3# 3#[69], 1:2:3# 3# 30#[69]°| 0]|

*] A]## 7H#°1#.

Everson: 0| 0]|*l #°H# (111)# (211)#0]| L|-E|-L|-# dislocation# 5#A|7|#E]|

*]#o|-Dj, lactic acid/HCl/HF# 2:4:15. 0] ®t 2## ^]##E|-[5]. Figure 6#

Everson §°-«£^ 0]|*]°H# [L| CZT0]| L(E(L(# ^## MO]##.

{a) f))

Figure 6. The typical surface morphologies of CZT (111 }B samples in (a, c) and (211 }B samples in (b, d) etched by Everson solution.

FeCl3 etchant: 10 ml®| H2O0]| 35g°| FeCl3# #0] ## §°-«££ H# CZT H#

°| dislocation pit# c>6|-#E|| A]-## C\.

Inoue-E solution: (111) ## L|-E|-I4|#E|| A]-#E| D^, HN03/H20/K2Cr207# 5 ml: 10 ml :

Page 30: CdZnTe - OSTI.GOV

2 g—| 9#^ 99 ##□], 1## 01|XI6h^[70],

Inoue E-Agl: 0| #2H# Inoue E-g-^Jlf AgNOs# 20 ml: lmg£| £[

1#9 011 XI oh cf. 0| §QH£ (111)9# fgopl 991 Af##9-

01|Xlo| 9^Lf etch pit£| 9EH# A|#£| ^°|(orientation^ EEfEf #2f99# 9#

99°H0f ohCf.

4.7. Te Inclusions and Precipitates

Te inclusionO| Lf precipitate# X-ray £f y-ray 1#7|£| A)|^.0||X1 #J2.°h 9

9- 9999 Te inclusion£| 3.7|# 9 10 |JmO||A-| 100 |JmAfO| 0| Dj [67,69], 99#

9S HU CZT 7|A|01|A1 hexagonal, cellular 9EH-£ 9#£|A|9 999°^ #99

oEH0| l£f[34], 9*| LH o| Te inclusion^ °1 #i# CZT 1#7| 99 A]6f£|

fl9 # 99^ 9HA| TLE^£|OlOf oh9. 0|E)oh 19# EJAKjOII £|6f| ^

99 Xf° 99# trapping °9£M| 1#7|£| 99# AiofA|#Lf. #6f£| trapping

# ##7|£| 01199 #9999 ofl|Ef 99 ## s#o||£ <g°f# o|99- 92(

A1 !9£| 99# 0|6H92L, ZL^£| 99# 9^f a|7|# #§9B# 9#1 1

fi7f Ofcf.

Te inclusionllf precipitate-9 9 oh §9 Lf 9 o' 9—I o999°|| X| 9999- 9#

Te£| 999 solid solubility £| l£fO| Ef[71], 199^ 99 A|^g{0| Lfm 99

99# 17] Lf #90| Te-rich 9EH^ 1 1#0]| 9999[34],

Inclusion# 99 99 oil a] 9EH9 #9999 19^ 99 919011 Ai 99921[68], 99011 precipitate# 19 99h #£| ^[97|#£f 99 99 #£| segregation

7|#0)|A1 7|999[67], ZL 19 #i# 92Leo| zj0|0|| EEfEf #7fofEf.

Te inclusion# OfE|]£| 990|| £|6f| 999# 9°^ #2]9 99- 9A] Cd #Af

7f «Q]*f7H 9E|01| £|6(| #901|A1 #999- 0| #9# Te-rich #9# 9#9 VcM Te 9## 9^A|99. Te 9## 9EH9 #999^ 99 SLIOJI trap92L,

450°C77fX| OHX]|9EH^ #AHohEf. 450oC0l|Ai 199 §£^1 99999].

SLI01I 999 inclusion# ofLf£| grain L(|^ 999 99- 99 19# 99 99 #0]| #£ #tiH01| £|oH 999 7]E|# 0|#6M| 9 #9, 0|# thermomigrationO^

92] A] o[9[34], Te inclusion# grain, subgrain, twin boundary# 9Lf?]| £| g E] 0|9

£| 0|## A||99 9. 0| 99# twin01 Lf grain boundary0|| HO] °[# inclusionlEs!

Page 31: CdZnTe - OSTI.GOV

^S£|D1, 0|# sitea ##[68], 0|# EE°h inclusion# ###a

°i# dislocation®| El#£ X|Q]# #g##C-||£ £#0| # #.

2|#°| 2#0]|X-] Te inclusionO| segregation coefficient7^ lM# ## Na, Ga, In, Bi

M yq^aa xipi## ^aa aaE|##. vm\ ai, Cu£H #

# Xfl7-j o|-X| #°1#. ZLE-] Lf- Te inclusion®! ### Xpi #&# #

°| 7|f^ LH7h -o| segregation 7|#0|| ®|°1 AHZJ£]#.

Te inclusion®! ##AH # ## ##0|| l=H ai SW @f7^ # °H£| oh #[2,68].

trapping# #7|#°| @^# CZT ##7|®| ### #go| Xlopl##.

7j|E|-7|- Te inclusion®! #XH# voltage breakdownaa #oH leakage current# #7|-A|

SaaAi ##7|®| #A1| H7|# ## # Sich 20 pmMCH # Te inclusion# #Xf-

#^0|| ##### 7^aa, ##7|7H aA^|ot# [[fl ## trapping a##

L|-EhtHiz|-[72]. bhHo^| #a# inclusiona ##7|®| ##0|| <gWS D|A|^# #a

S^Of °1#. ##7|®| #6H#0|| got# □!*!# inclusion®! £|a H7|0|| EH#

o^[# bI1|-# SlaLK # micron 0|o|-o| inclusion# 0|| L| A| #6H#0|| H7j|

# 0|^|X| ## #aa a##.

Te precipitate# #'§## 2i7| y-7fl0|| A] Te # A(-°| five neighboring Tfaa ##

£|Ef|[31], 2Jaa7H yz|£|# H^O!|Ai ax)|#aa Precipitate®! ###

oiaa #x)|o!| ## Te ##o|| °PH xM##. 90% o|#®| a# Te# ##E|Eq,

Te°| o solubility# >—iE|-lH E|-. Precipitate# EH# 10-50 nm -§a°| £=L7|0|[#

# 50~80%7H Teaa ##E|0] ®l#. Te°| #a0|| ## # ##®| nano #a# #

## # Si-bkll, Te°| #a7H #### ###0|| 7[7}[°D\, ## #a°| Te###

a # EH7|- ##0|| 7|-5 * 7#E|-[47]. Precipitate #9 °| dislocation# trapping X|-E| ®| ##

# Op I [LH#0!| precipitate®! #i7f- #### @#7|®| ##0| ##A|# ## g

## #0|#.

5. Annealing

Te inclusionO| Lf- precipitate #X)|# S#6|-7| #|oH A] # ## ## # #Aj E|#^

OH CH# @f7f A|#0|| # #tiH# 7f#aa#, inclusionO|Lf

precipitate®! thermo-migration# #a# # Sa#[31]- 0| CEH Te°| melting point 0|#

aa #Aia| #a# #7p|g## thermo-migration# 7H#A|# # ®!## ^# #

□|a# #0|#. I^aa annealing# Cd ##7|0!|Ai 0| ### #&H

Page 32: CdZnTe - OSTI.GOV

Cd8 VcdS M^opl °lHM ^AhEla, ^gOjl Te^ A|g <glAh

0|M. ®I°H Te inclusionO| Lf- precipitate®] EL7|2]- 1=JE§ SlU]-74.2.51 4"

5i^[34],

Annealing^ CZT #^0|| S 7[X\ 0|g# 7^£S. g7| X]%^ 2^41 0]^

#7^A|7|S[30], y# §a ^ 4 5i^[64], EE°h §I°J2]

°l 1^# ^A|7|D1[64]. n^o\ m E] MU 4 5i^[30], Vcd#

compensationo|-Dj dislocation®] ^£| 4" °a^I"[73]. E|-A| °|M.sl Te precipitate

®| H7|# 2 |Jm 0|6|-M ^MA| 7] D} [31], Te inclusion®] ?hMA| S C|-[2].

Figure 7# MS annealing ^0]| Te inclusion®] SO] °iX-]6|-?]| #0]-^ ^1# §]oj|

4 °ich

Figure 7. IR microscope image of CZT sample before (a) and after (b) annealing at high temperature in Cd-rich ambient[74].

S 7|-A| annealing SgO] 7|^£|0] MME]®^, Z| SS°I

0]| 7|#6^^.

Annealing under Cd vapor pressure at various temperatures to dissolve Te inclusions[75]: nrS cMI 7|X]]S 2i|74 °| 2iSrr 850°CO]| A] 200A |S annealing o|-7-j

Page 33: CdZnTe - OSTI.GOV

L|-[76] 950°C01|A1 lOA|7h 0|^ annealing 6|-# ^0| E|-[31].

Two-step annealing: Two-step annealing# E)-## #0| E|-. 1 EMI si Cd0.99Zn0.01

—I o-^l tdh 'oEH°l|Ai annealingo|-# E|| A|## °f 800°C, Cd0.99Zn0.01—I source# 600°C

0\\k\ #A|A|#E|-. Annealing A|#1# 50 A|#0|E|-. 2 A|## 600°C^ #A|A|

U cdo.99Zno.01 #oj| ^^^[73]. #i£f a|#i# ^#oj| cq-ah e^|

M2LE|2L $M[64].

Annealing under Cd and Zn vapor pressure: A| ## 800oC0]| A] annealingoj-EL CdE^

Zn source# ZJZJ 850°C£f- 650°CO]| A] 120h -§-£1 #$^#E|-. Annealing ^Oj|# #

yo| yz|A|^Of °lE|-[29].

Low-temperature annealing under H2 atmosphere(150°C): H2 #A|-# Te# A(-2|- ###

# ^Oj TeH2# ##Eh H2# #^2| complex# ##a^1 Oj Ei #^A-||

AH^O]|Ai ###2^ deep level# passivation A|7|# #E^A] °IE|-.

Annealing under indium atmosphere: Indium# InCd(donor) EE# InCdVcd(A center)^.A

^ O# A- InCd donorEf- VCd acceptor A|-0| °| Afl#*1-# p-type AH^.°| #of- #EE# A

4iA|7|ZL, n-type A^o| @^A|^|L|-. 0| #§# 600°COj|A-| 240A|7_1 5#

800oC0]| A] 6h ## 0|#0] # E|-. 600°C£f- 800oC0]| A] °| indium°| diffusion coefficient

# A A 10'n4 10'9cm2/s0| E|-[76].

Page 34: CdZnTe - OSTI.GOV

IV. Characterization

CZT ##A|# oOjl- g7|# #^# #7[6[7| #6H ^ 7[X| #

# tool# 0|#o[# %0\ #56[E[. # ^OllAlb CZT# #^# #7[6[7| #6H A[

£ #a| #5 ## ^ao|| CH6HX1 7|#oU^ ##.

1. IR microscopy

IR microscopy# Te inclusionO| L[ precipitate^^ #"# ### 57| L[ #5# #-§o[

7| °|oH A[## E[[67], # *gj# # IR A|5@{# large field view microscope objective,

motorized translation stage, light source, 5#oH## 7[# CCD 7[0fl E[ #5.5. ##E|

0] inclusion01 L[ precipitate# £\E #EH°I @# #55 50|Et| 5# £\E

#55 tiH«E|(}] OICK

IR microscopy# 0|-g-6[Q| #1## TE precipitate# #X[j# #h# #o[ ###^#

## ##"#"711# ^"#C|-[68]. #X[### electrostatic repulsion# precipitate## #

#### ##0]| EH# ##5 55###[67].

2. Resistivity

## #7|X]#I# ##7|5 A[##7| ## CZTOH# ###0|E[. Aj&I# 7|# #

#0| ## A]#I# ##A|# ##o[7| #6H ##7|# A]|#o[# 57| Em|A] g

7[##0[ ##. Xjot ##7|(COREMA)# A|# #X]|0]| #*j A]#!# °«

#o[# xtX|0|E[. 7]| E[7[ as-cut #EH# A|## 7[A|55 #A[# ^ #

#.

#501| ## A]oto| 5A]ot p-tyep# A]A]ot n-tpye ## 5#0j|

A] #0|5# #5# A1|##1E[[77], A]°I# Al, Mn, Ga# ## deep donor# #57[

#7[### #7[o[5, #301| Li,Na,Cu# ## shallow #### #57[ #7[##

# #5#E[. I/V 5# C/V #g# 0|#°h ##### Au contact01| EH# #«#0|

# uxS #5 contact# passivation ### #W## # 2]#E[[60].

3. Near IR Spectroscopy

NIR spectroscopy# CZT L[](#1 Zn# #5# #### #7[o[7| °|oH A[-g-## H|

H[# #A[SO|E[[60], Working H[## #0|# 825-850 nm0|Q|, 0| #g# 5gA]E|

# EH 01| OH# ei###[78], ##S01|# # 7[A|7[ °i#E||, o[L[^ cut-off

wavelength# 0|-g-6[Q| 825-850 nm01|A] band-edge transmission# #'§o[# ^10|5,

Page 35: CdZnTe - OSTI.GOV

5E o)L)t=. cut-on wavelength# 0|#o)# 01 C|-.

4. Fourier Transform IR microscopy

FTIR spectroscopy# #-§-# o-S-S ##7|#0|[I). # fiS# #A)# #6^

(reflectance losses)# ZilE)6)g, 0|-[§-# ®l transmittance# 500-4000 cm-1# ^ °|0]| A)

# 66%0|E)[79], 0| wo|^ ##, dislocationOj] EH# #a# §

M# #E).

a. A)# #6)# g^H# IR spectrum0j| ### 0| A|0), spectrum# #IE7) A)# #

°)# #i7) #7)### #4h6)# 3## M#E)[29]

b. precipitate L) inclusion# ## ### scattering^) absorption# #6H IR

transmittance# #4iA|7|# ##0| #E)[2],

c. dislocation®! #Afl# ^ A) ### 9 # A| 7|ZL, IR radiation# S# -S-#,

transmission spectrum #_E# #4iA| # E)[35],

Figure 80j| IR transmission spectra®] # 7)A| #EH# l)E)LH#E). #7)6)7-) L)

o)# ^EH# M0|# %# dislocation #i7) ^)7-)L) ## ##0|E)# °|□ 101D),

## ## ^EH# ## dislocation density# Ai### ## ##0|E). #g0]|

## ## ^EH# dislocation density# ## Ai### ## AH## #D|6)#

#0|E).

40 v-

Wavg numbgr(cm ’)

Figure 8. Four types of IR transmission spectra: (a) descending type, (b) ascending type, (c) low straight type, and (d) high straight type[80]

Page 36: CdZnTe - OSTI.GOV

5. Photoluminescence Spectroscopy

X1£OU10| PL A|#0||A| Zn a§°| nJ]™, band gap #§, #0# #4

2*!j, aXl## °|# #9I O|0§4. PL 7|#0 free

exciton£| 049\ donor-bound exciton, acceptor-bound exciton E|-§£| #6f|

cH4#aa S4S 7^1 4 SM. !§°l 4a# 4§# #4#9I o|

oH ##10 band°| §aa §7Hh 0 ^a#, 7|0*aa PL 7|#0 g

A] §S4 0|-L| E|-[79].

PL ## 1491*1 #a#4l Mb 004 o)-eH4 14.

a. free exciton!^ §§§ 1.66 eV£| near-band-edge 1# 10 914X| 1 4 oil #

6H Zn a§# 444491 A^b!4. 9IMx| l£| H7|0 o|-eh£| Ajaa 0#

4 5i4-

Eg = 1.606 + 0.520x + 0.254x2

471A] x0 Zn 0#o|#. Zn£| §#00 a#a°| CZT 4^91 4901 44

§o|-E|-[42]. The near band gap §44 a##£| n-type9l Cf]4k\0 donor-bound

exciton peak(D,X), a##£| p-type9l Lfjof]A-jacceptor-bound exciton(A,X)§

bound exciton lines9l °|6H X| E|-[25]. §#§£| #0 A|§°| §4#§ #1

# 4 4 §4

b. donor-acceptor (D-A) §44 4s°l donor X| Llf]0 § XjXj§£| n-type 4-ElLf- Cd

vapor0j| Aj£| annealing #§91 ^J-o^ Aj §00 E|-. 0X|-£| §4 Cd interstitial01

K4 4a°| §4 Vcd°l 4a# 14a, (D,X)/(A,X)£| w|## #§4.

C. i.4~i.5 eV §44 4# 44(Vcd-Mcd)°l 400§ 14aA&l !§4 §§§ PL

£| broadband §#0|E|-. Oj7|A] M0 In, Ga, AlILf 10 #0#O|E|-[42]. §§#

§ 0]|aAl M §§§ #0 1# [2Incd+-Vcd"2]°| §#0|4, O|0 In0| a§§

CZT0]|A] Vcd# compensation#E|-. DislocationO]| £|# §# a# °|£| §4914

§4 §4, passivation #§ 491 7|§§ E|-[81].

d. 1.0-1.1 eV § 4 a| #a §#0 Te vancancy[82]£|- Fe, Cd vacancy 4#91 4°H

44§4[25],

6. X-ray Photoelectron Spectroscopy

Page 37: CdZnTe - OSTI.GOV

XPS# ?|6H AH###. # # #*||Aj°^, passivation ##

^o[0\ OjEi ##o| ^oh AiE|S oh O HSS #A]## #0|Eh 0| ### #6H Br-MeOH ## 0||# #°| Te-rich #2H passivation °°| Te02 #Oj|A-| Te/(Cd+Zn)

°l HIM ^1^# 4 Sffl83].

7. Other Characterization Techniques

?|0t| 7|#°h ## Hhg 0|£|0||£ ### gAp|gO| ####. #X| induced

coupled plasma spectroscopy(ICP)# 0|-g-o|-0j Al, Ga, Li, Na, Mn, Cu# ## ####

ppm El" ° I0### # 4" Si— #, glow discharge mass spectroscopy(GDMS)# 01 -g-

o|-0j H# ##0j| EHoHA] #A{ sh 4" Sich Atomic absorption spectrometry(AAS)# 1%

01 L|]£| #A] 7|~^6|-ZL, E|-A|°|H^. energy dispersive X-ray analysis(EDAX)

h 8f£L[ EH # £| y^A]S # - oicK

X-ray diffraction(XRD)-# lattice parameter# #Aj o|-Et|^ ###.2.51 Vegard # ##

0|#6|-0j CZT°| ^## ### # oi q. High resolution X-ray diffraction(HRXRD)#

^OjEJ #-§ #0]| EHo|-Oj full width at half maximum## Aj|-#AhE|-. 0| ## ^H-^-—I

#1# ##E|0| Si Ah CZT°| ## 7^ ## ### <211>0H EH oH A] Qt g

arcsec°| #0| #^##[42]. Scanning spreading resistance microscopy# 2.# fi# #

AjOjlEJ" oj-o|-0|, #o| Te precipitate Lf- inclusion# #A|o|-#Ej| ##o|-E|-.

Photocurrent(PC) #A] ## #o|-°| mobility lifetime, ##"—I l!°H—I 7| Q]_E., contact

#1, #7|#°| #2 ## ####E|| AH## Eh

Page 38: CdZnTe - OSTI.GOV

V. Conclusion

CZT oh^ S|0 °|S7|7|, MOh^AH ^o| a^7p^| ^gO||Alo|

#[|j5pL °Ph ZLEip 0^77p|^ 2L#1 ^ 3^3°l ^o[

X| ^§0|Eh #6| ^LH01|A1o| CZT 33 ^ #3 @7h0|| @

M p^°| ytHsp, oij= 33oph °pn

77p|o| CZT @f£| 33^ ^ 7p|^ Pit - oi-ct 6p^ L^ ##

XII 0]S #oh 1§0| =5| oNAh g^L0|2L, P# ofLp ££ 3334 P# 33

# 43 [|jf34o|p. 3x^3 yix-l 313 33, 3x^, 35>33 3 334 # 333 go^# 5°Jop oiolk ^330|ZL 334 ^MOjl #P33

P33 3xi°| ^4# 4333 313 33 3 ^I337|- P^opf- #4 33 34X1 3P 3xto yiA-| go^Pl 333 qp| 33 44 S ^Mop| 44X13 313 334 43 3f7^ 44 #34 334401: 44, o|o|| 43 #3 7|ir ^M7h 1^3Oph

Page 39: CdZnTe - OSTI.GOV

Reference

[1] , Li G, Jie W, Hua H, and Gu Z (2003b) Progress in Crystal Growth and Characterizationof Materials 46: 85-104.

[2] , Szeles C and Driver MC (1998) Proceedings of SPIE Conference on Hard X-Ray andGamma-Ray Detector Physics and Applications. San Diego, CA, USA.

[3] , Audet N, Levicharsky B, Zappettini A, and Zha M (2006) IEEE Transactions onNuclear Science 54(4): 782-785.

[4] , Cui Y, Bolotnikov AE, Camarda GS, et al. (2007) IEEE Transactions on NuclearScience 54(4): 849-853.

[5] , Mandal K, Kang SH, Choi M, et al. (2007) IEEE Transactions on Nuclear Science54(4): 802-806.

[6] , Triboulet R (2005). Physica Status Solidi (c) 5(2): 1556-1565.

[7] , Greenberg JH and Guskov VN (2006) Journal of Crystal Growth 289: 552-558.

[8] , Szeles C (2004) IEEE Transactions on Nuclear Science 51(3): 1242-1249

[9] , Greenberg JH (2003 Progress in Crystal Growth and Characterization of Materials47(23): 196-238.

[10] . Greenberg JH, Guskov VN, and Alikhanyan AS (2003) Crystal Research andTechnology 38(7): 598-603.

[11] . Auricchio N, Marchini L, Carol! E, et al. (2008). IEEE Nuclear Science SymposiumConference Record R12-R30: 250-253.

[12] . Fiederle M, Duffar T, Garandet JP, et al. (2004 Journal of Crystal Growth 267 (34):429^135.

[13] . Lun L, Yeckel A, Reed M, Szeles C, Daoutidis P, and Derby JJ (2006) Journal ofCrystal Growth 290(1): 35-43.

[14] . Owens A, Bavdaz M, Andersson H, et al. (2002) Nuclear Instruments and Methods inPhysics Research A 484(13): 242-250.

[15] . Zhang Z, Gao H, Jie W, Guo D, Jang R, and Li Y (2008b) Semiconductors Science andTechnology 23: 105023-1-105023-9.

[16] . Juncheng L (2008) Crystal Research and Technology 43(4): 396-408.

[17] . Marti nez-Toma' s C and Munoz V (2001) Journal of Crystal Growth 222(3): 435-451.

[18] . Fougeres P, Hage-Ali M, Koebel JM, et al. (1998) Journal of Crystal Growth 184/185:1313-1318.

[19] . Castaldini A, Cavallini A, Fraboni B, Polenta L, Fern' ndez P, and Piqueras J (1996)Material Science and Engineering B42(13): 302-305.

Page 40: CdZnTe - OSTI.GOV

[20] . Li G, Jie W, Gu Z, and Hua H (2004a) Journal of Crystal Growth 263(14): 332-337.

[21] . Guskov VN, Greenber JH, Fiederle M, and Benz KW (2004) Journal of Alloys andCompounds 371(1-2): 118-121.

[22] . Shcherbak L (2004) Journal of Alloys and Compounds 371(12): 186-190.

[23] . Triboulet R (2003) Crystal Research and Technology 88(3): 215-224.

[24] . Fiederle M, Babentsov V, Franc J, Fauler A, and Konrath JP (2003) Crystal Researchand Technology 38(7-8): 588-597.

[25] . Babentsov V, Franc J, Fauler A, Fiederle M, and James RB (2008) Journal of CrystalGrowth 310(15): 3482-3487.

[26] . Awadalla SA, Hunt AW, Lynn KG, Glass H, Szeles C, and Wei SH (2004) PhysicalReview B 69(7): 075210-1-075210-4.

[27] . Krsmanovic N, Lynn KG, Weber MH, Tjossem R, and Gessmann T (2000) PhysicalReview B62(24): 16279-16282.

[28] . Kim K, Cho SH, Sub JH, Hong J, and Kim SU (2009) IEEE Transactions on NuclearScience 56(3): 858-862.

[29] . Li G, Jie W, Wang T, and Yang G (2004b) Nuclear Instruments and Methods inPhysics Research A 534(3): 511-517.

[30] . Li G, Zhang X, Hua H, and Jie W (2006a) Semiconductors Science and Technology21(3): 392-396.

[31] . Koyama A, Hichiwa A, and Hirano R (1999) Journal of Electronic Materials 28(6):683-687.

[32] . Wang T, Jie W, Zhang J, et al. (2007) Journal of Crystal Growth 304(2): 313-316.

[33] . Franc J, Grill R, Jubat J, Belas E, Moravec P, and Hoschl P (2007) IEEE Transactionson Nuclear Science 54(4): 864-867.

[34] . Szeles C, Cameron SE, Ndap JO, and Chalmers W (2002) IEEE Transactions onNuclear Science 49(5): 2535-2540.

[35] . Fiederle M, Fauler A, and Zwerger A (2007 IEEE Transactions on Nuclear Science54(4): 769-772.

[36] . Yang G, Jie W, Li Q, Wang T, Li G, and Hua HJ (2005) Journal of Crystal Growth283(34): 431^137.

[37] . Komar V, Gektin A, Nalivaiko D, et al. (2001) Nuclear Instruments and Methods inPhysics Research A458: 113-122.

[38] . Zappettini A, Zha M, Pavesi M, and Zanotti L (2007a) Journal of Crystal Growth307(2): 283-288.

Page 41: CdZnTe - OSTI.GOV

[39] . Fiederle M, Feltgen T, Meinhardt J, Rogalla M, and Benz KW (1999) Journal ofCrystal Growth 197(3): 635-640.

[40] . Ivanov YM (1998) Journal of Crystal Growth 194(34): 309-316.

[41] . Kestigan M, Bollong AB, Derby JJ, et al. (1999) Journal of Electronic Materials 28(6):726-731.

[42] . Asahi T, Oda O, Taniguchi Y, and Koyama A (1996) Journal of Crystal Growth161(14): 20-27.

[43] . Li W, Sang W, Min J, Yu F, Zhang B, and Wang K (2002) Semiconductors Scienceand Technology 17(10): L55-L58.

[44] . Li Q, Jie W, Fu L, et al. (2006d) Journal of Crystal Growth 295(1): 124-128.

[45] . Terterian S, Chu M, Ting D, Wu LC, and Wang CC (2003) Journal of ElectronicMaterials 32(7): 796-802.

[46] . Turkevych I, Franc J, Grill R, Hoschl P, Belas E, and Moravec P (2004) Journal ofElectronic Materials 35(6): 658-661.

[47] . Carini GA, Bolotnikov AE, Camarda GS, Wright GW, and James RB (2006) AppliedPhysics Letters 88: 143515-1-143515-3.

[48] . Chao CK and Hung SY (2003) Journal of Crystal Growth 256(12): 107-115.

[49] . Derby J, Kuppurao S, Xiao Q, Heckel A, and Zhou Y (1995) Large-scale numericalmodeling of bulk crystal growth from the melt and solution. In: van der Eerden JP and Bruinsma OSL (eds.) Science and Technology of Crystal Growth, pp. 111-122. Dordrecht: Kluwer.

[50] . KurzM and Muller G (2000) Journal of Crystal Growth 208(14): 341-349.

[51] . Gasperino D, Bliss M, Jones K, Lynn K, and Derby JJ (2009) Journal of CrystalGrowth 311: 2327-2335.

[52] . Edwards K, Brandon S, and Derby JJ (1999) Journal of Crystal Growth 206(12): 37-50.

[53] . Wang Y, Kudo K, Inatomi Y, Ji R, and Motegi T (2005) Journal of Crystal Growth284(34): 406-411.

[54] . Antonis PD, Morton EJ, and Menezes T (1996) Nuclear Instruments and Methods inPhysics Research 380(12): 157-159.

[55] . Careden V, Vijayan N, Rodri'guez-Fern' ndez J, et al. (2009) Journal of CrystalGrowth 311(5): 1264-1267.

[56] . Toney JE, Schlesinger TE, and James RB (1999) Nuclear Instruments and Methods inPhysics Research A 428(1): 14-24.

[57] . Zappettini A, Zha M, Pavesi M, et al. (2007b) IEEE Transactions on Nuclear Science54(4): 798-801.

Page 42: CdZnTe - OSTI.GOV

[58] . Pandy A, Yweckel A, Reed M, et al. (2005) Journal of Crystal Growth 276(12): 133—147.

[59] . Moravec P, Hoschl P, Franc J, et al. (2006) Journal of Electronic Materials 35(6):1206-1213.

[60] . Cheng X, Zhu S, Zhao B, He Z, Gao D, and Fang J (2007) Applied Surface Science253:8404-8407.

[61] . Dost S and Liu YC (2007) Comptes Rendus Mecanique 335(56): 323-329.

[62] . Mullins JT, Cantwell BJ, Basu A, et al. (2008) Journal of Electronic Materials 37(9):1460-1464.

[63] . Tao Y and Kou S (1997) Journal of Crystal Growth 181(3): 301-303.

[64] . Zeng D, Jie W, Zha G, Wang T, and Yang G (2007b) Journal of Crystal Growth 305(1):50-54.

[65] . Li G, Shih SJ, Huang Y, Wang T, and Jie W (2008a) Journal of Crystal Growth 311(1):85-89.

[66] . Rose D, Durose K, Palosz W, Szczerbakov A, and Grasza K (1998) Journal of Physics:Applied Physics D 31(8): 1009-1016.

[67] . Bolotnikov AE, Camarda GS, Carini GA, Cui Y, and Kohman KT (2007) IEEETransaction on Nuclear Science 54(4): 821-827.

[68] . Camarda GS, Bolotnikov AE, Carini GA, and James RB (2006) Effects of telluriumprecipitates on charge collection in CZT nuclear radiation detectors. In: Countering Nuclear and Radiological Terrorism, eh. 4, pp. 199-208 (ISBN 978-1-4020-4897-5). Dordrecht: Springer.

[69] . Asahi T, Oda O, Taniguchi Y, and Koyama A (1995) Journal of Crystal Growth149(12): 23-29.

[70] . Bissoli F, Armani N, Salviati G, et al. (2004) Physica Status Solid! (c) 4(1): 735-738.

[71] . Duff MC, Hunter DB, Nuessle P, et al. (2007) Journal of Electronic Materials 36(8):1092-1097.

[72] . Chen H, Awadalla SA, Mackenzie J, et al. (2007) IEEE Transactions on NuclearScience 54(4): 811-816.

[73] . Yang G, Jie W, Zhang Q, Wang T, Li Q, and Hua H (2006) Transactions of NonferrousMetals Society of China 16(1): sl74-sl77.

[74] . Belas E, Sugar M, Grill R, et al. (2007) Journal of Electronic Materials 36(8): 1025-1030.

[75] . Grill R, Franc J, Hoschl P, et al. (2007) IEEE Transactions on Nuclear Science 54(4):

Page 43: CdZnTe - OSTI.GOV

792-797.

[76] . Zhang X, Zhao Z, Zhang P, Ji R, and Li Q (2009a) Journal of Crystal Growth 311(2):286-291.

[77] . Xu Y, Jie W, Selllin P, et al. (2009) Journal of Physics D: Applied Physics 42(3):035105-1-035105-6.

[78] . Capper P (2005) Bulk growth of CdZnTe/CdTe crystals. In: Hirano R and Kurita H(eds.) Bulk Crystal Growth of Electronic, Optical, and Optoelectronic Materials, Section 8, pp. 149-172. Hoboken, NJ: Wiley.

[79] . Franc J, Moravec P, Hlidek P, et al. (2003) Journal of Electronic Materials 32(7): 761-765.

[80] . Li G, Jie W, Gu Z, and Hua H (2003a) Chinese Physics Letters 20(9): 1600-1603.

[81] . Li Q and Wanqi J (2006e) Nuclear Instruments and Methods in Physics Research A562(1): 468^171.

[82] . Li G, Zhang X, and Jie W (2005) Semiconductors Science and Technology 20(1): 86-89.

[83] . Cho SH, Suh JH, Won JH, Kim KH, Hon JK, and Kim SU (2008) Nuclear Instrumentsand Methods in Physics Research A591: 203-205.

3 6

Page 44: CdZnTe - OSTI.GOV

A1 A| ^ M & A]

^oH7|^iHAiyS ?|Et7|^MaAigS H^aaAigs INIS ^ All as

KAERI/AR - 886/2011

All ^ / VA1I CdZnTe gg 54 ^g^7h g? sw bg

9^9*^ ^ “A1§(AR,TR #2| ^*W)

o|b5, yAKd7|7|g^v

^ ^ X\ % “ A1 g gg^, g°hb yA^7|7|9^V

# 9 A| qotnj^ ^7|9 °i5§R99b9 9^9 2011

Ell 0| A| p.44 S H 9#(0), a#o a 7| 27 Cm.

gsA^

g7MV #7H(0), U|§7H()MSAj## 7|#9#b9MSA]

999^ 9990, 599

9^?l^7|^ 9199^

b# (15-20 #4 £|)

CdZnTe (CZT) °|S7|7|, M°^AH #o| ^7^* a^0||o| §§o^ oj$y

#ago| °ib 9a*il ^X|0|Qh ^^71 ?|6HAlb

# 54 7|-a| £JH\7[ ^o^oiolk o| e^^oil q°[ g^g !ago| #q#MI ^ £|iggg aaAiiaqi q*j g^7h gi^gas #^| 0|f^x|3. °ihk

g aaxi^Aib gygy czt e^g ggur #g@z^i 9? ##^i ch*h 7|#6^x^ *mh9*1, CZT °| !ZQ?} Phase diagram 0]|Ai 7|°j°I °A-j|g# gg°I s CZT o| compensation 7H^H|-

^gur ewi nyg9 ^ai. s^g #g# g§°[ch e^g# gg^g gg°[g@6^ #o|. gg a|o|| ggi ^ 9b ^g^l bg# 9^9 7|#6^x^ *mh esj ^g°| #g# ygzizibcii i^gy 9*iai gga g§°ig. dw^i, ggg eig°i #g#

4# yg# 7|#6^A^ *mh

^A1|g7|^H(10 EI-CHLH2J)

czt, g^g, &AKd 7||^7|

Page 45: CdZnTe - OSTI.GOV

BIBLIOGRAPHIC INFORMATION SHEET

Performing Org. Report No.

Sponsoring Org. Report No.

Stamdard Report No. INIS Subject Code

KAERI/ AR-886 /2011

Title / Subtitle Analysis of Study Trend of Growth and Characterization of CdZnTe Single Crystal

Project Manager and Department

(or Main Author)Kyuhong Lee

Researcher and Department Jang Ho Ha, Han Soo Kim

Publication Place

Page

KOREA

p.44

Publisher

111. & Tab.

KAERI

Yes(O), No ()

PublicationDate

Size

2011

27 Cm.

Note

Open Open(O), Closed()

Classified Restricted(), Class DocumentReport Type State of art report

Sponsoring Org. Contract No.

Abstract (15-20 Lines)CdZnTe (CZT) alloys are very important semiconducting compounds due to their use in

several strategic applications in medical, space, and security devices, especially, radiation detector. Specific problems of the bulk crystal growth are still to be solved. However, since industries require excellent bulk CZT crystals, a strong effort is being organized worldwide to optimize the growth process and obtain better material.

This report presents the study trend of the bulk CZT crystal growth and characteristics. After the first section where the problems connected to the complicated phase diagram of CZT are presented, the second section describes the various general physical and chemical properties, together with the compensation problems of the CZT material. In the third section, various growth methods are described, paying attention to the defects generated in the different cases. Further, the annealing process which is an essential step for improving the crystal quality is described. In the last section, the general material characterization methods are presented, as a scientific approach for assessing the quality of the bulk crystal.

Subject Keywords

(About 10 wordsjCZT, Single Crystal, Radiation Detector