Supplementary information …iopscience.iop.org/0957-4484/25/42/425201/media/nano...Supplementary...
Transcript of Supplementary information …iopscience.iop.org/0957-4484/25/42/425201/media/nano...Supplementary...
Supplementary information
Electrical properties of GaSb/InAsSb
core/shell nanowires
Bahram Ganjipour, 1, a) Sobhan Sepehri1, Anil W. Dey2, Ofogh Tizno1, B. Mattias Borg3, Kimberly A.
Dick, Lars Samuelson1, Lars-Erik Wernersson2, and Claes Thelander1, a)
1 Solid State Physics, Lund University, SE-221 00 Lund, Sweden 2 Electrical & Information Technology, Lund University, SE-221 00 Lund, Sweden
3 IBM Research Zurich, Säumerstrasse 4, 8803 Ruschlikon, Switzerland a) Authors to whom correspondence should be addressed. Electronic mail: [email protected] and [email protected]
Figure 1: SEM images (52° tilt) of GaSb-InAs core-shell nanowires after selective
etching of the InAs shell using citric acid:hydrogen peroxide (2:1) solution for 12
seconds.
500 nm
500 nm
500 nm
Figure 2:(a) the intrinsic conductance versus gate voltage for GaSb/InAs core/shell NW device with an intermediate InAs shell thickness of 5-7 nm. The nanowire shows ambipolar semiconducting behavior, with ρ i = 24 mΩcm at VGS = 0 V and contact resistance of Rc= 1 kΩ. For negative gate voltages the GaSb core is populated with holes, and the shell is depleted from charge carriers, giving a p-type back-gate response. For sufficiently positive gate voltages the InAs shell is populated with electrons, which leads to an onset of n-type back-gate behavior. (b) The field effect mobility of the nanowire as a function of gate voltage. (c) The Carrier concentration versus gate voltage.
−10 −5 0 5 1060
70
80
90
100
110
120
VGS(V)
G(µ
S)
Tshell~ 5-7 nm
GaSb
InAs
a
b c
−10 −5 0 5 100
100
200
300
400
VGS(V) VGS(V)
Mob
ility
(cm
2 / V
s)
Car
rier C
once
ntra
tion(
cm3 )
−10 −5 0 5 101018
1019
1020
Figure 3: Room temperature field effect mobility of a few different GaSb/InAs core/shell and GaSb NWFETs vs gate voltage.
Figure 4: (a) The contact resistance vs. VGS at different temperatures for GaSb/InAs core/shell NWs. (b) Extracted activation energies from the temperature dependence of the contact resistance. (c) The total device resistance (R2P) vs. VGS at different temperatures for GaSb/InAs core/shell NWs. (d) Extracted activation energies from the temperature dependence of the total device resistance (R2P).
Figure 5: AC performance of a GaSb/InAs core/shell nanowire based frequency multiplier. Input and output waveform for (a) an input 10 kHz and (b) an input 20 kHz.
a
0 100 200
-2.0
-1.0
0.0
1.0
-2.0
-1.0
0.0
1.0finput = 20 kHz
V outp
ut (V
)
V inpu
t (V)
Time (µs)
V intpu
t (V)
Time (µs)
V outp
ut (V
)
finput = 10 kHz
b