Semiconductor Nanostructure Acoustodynamics
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Transcript of Semiconductor Nanostructure Acoustodynamics
Semiconductor NanostructureAcoustodynamics
Jens Ebbecke
Linz 25/06/09
outline
acoustoelectrics acoustooptics fibres and hybrids
GaAs
kikklikli
kkijklijklij
ESeD
EeScT
one kind of solutions: surface acoustic waves
first investigated in 1885 by Lord Rayleigh for earth quakes
surface acoustic waves
f = cSAW / p
nanostructure
Surface Acoustic Waves and
Semiconductor Nanostructures:
the electronic part
Acoustoelectric Current Device (SET-SAW)
3 m
100 nm
700 nm
700 nm
RF Drive ofFrequency f
Current = e·f
Gate Voltage
Current Plateaus
f = 3.58 GHz
P = 16 dBm
T = 1.7 K
I = e f
-2.2 -2.1 -2.0 -1.9
0
1
2
3
4
5
.
Cur
rent
/ nA
Gate Voltage / V
700 nm
700 nm
Vgate
2D data
Vgate
RF Amplitude
I=2ef
I=ef
I=3ef
RF Amplitude
-1.1
2 V
-1.2
0 V
Interaction of SAW and Impurity dot
Vga
te
RF Amplitude-30 dBm 0 dBm
PRB 68, 245310, (2003)
charging energy of a conductor: EC = e2/C Coulomb blockade
EC = e2/C >> kBT
RT >> h/2e2
zero-dimensional electronic system:
energy quantisation :
total energy:
Δ E = EN+1 - EN = Δ + EC
EF ΔE
Semiconductor quantum dots
quantized current through a static quantum dot
APL 84, 4319 (2004)
RF Amplitude
Gat
e V
olta
ge
I = 1 ef I = 1·e·f
I = 1 e f
I = 2 e f
I = 3 e f.
..
.
..
0
2
Cur
r.
/ n
A
I = e·f
Acoustic turnstile device
-1.1
2 V
-1.2
0 V
V
gate
RF Amplitude-30 dBm 0 dBm
a) b)
a)
Exciting: an Archimedian screw for electrons
PRB 72, 121311(R) 2005
(picture taken from Science,304, 1079 (2004)„Highlights of the recent literature“)
Charge pumping in Carbon Nanotubes
New J. of Phys. 9, 73 (07)PRB 70, 233401 (04)
I = e·f
1m
SAW and GaN nanowires
Nanotechnology 19 , 275708 (08)
400 nm
SiO2 / Au
GaN
Surface Acoustic Waves and
Semiconductor Nanostructures:
the optic part
Single photon source by bipolar charge transport
GaAs
GaAlAs
GaAs-Quantumwell
Single photon source by bipolar charge transport
PRB 74, 035407 (06)
ZnCdSe/LiNbO3- Hybrid
Epi-Liftoff of ZnCdSe-QWonto LiNbO3 substrate
Finally...
Organic nanofibres
and new stuff
Growth of Carbon Nanosticks
Laser ablation of carbon leads self-organisationof carbon nanosticks->Pyroelectric effects responsible for nanostick growth-> organic nanowire son LiNbO3
p6P nanofibres on LiNbO3
Standard white LiNbO3 Black LiNbO3
p6P nanofibres on LiNbO3
5 µm
5 µm
Post-Growth cleaning withTrimethylpentane
Growth on prestructuredmetal electrodes