n型ドープGaAs量子細線の発光および発光励起スペクトル

n型ドープGaAs量子細線の
発光および発光励起スペクトル測定
東京大学物性研究所,CREST（JST）,Bell Lab
井原章之,早水裕平,吉田正裕,秋山英文,
Loren N.Pfeiffer,Ken W.West
１、introduction
２、sample
３、PL and PLE of wire
４、electron density dependence
５、wire / arm well
６、Theory
７、conclusion and problems
introduction
Low dimensional electron system
Fermi Edge Singularity in 1D system ?
1D Luttinger Liquid ?
Electron density dependence of
Photoluminescence (PL) and PL Excitation (PLE)
Spectra in an n-type doped 1D Quantum Wire
sample
 grown by CEO with MBE
 stem electron density
1×1011 cm-2
 Gate Voltage（Vg）
0.0～0.8V
wire density
0～4×105 cm-1
arm density
0～1.3×1011 cm-2
 Temperature
5K (Liquid He)
PL and PLE of wire
PLE ～
same information with
absorption spectrum
PL and PLE Intensity (arb.units)
wire HH
Vg=0.15V
LH：light hole
HH：heavy hole
PLE
arm HH
arm LH
stem LH
PL
stem HH
1.55
1.564 1.568 1.572
Photon Energy (eV)
1.57
1.59
1.61
1.63
Photon Energy (eV)
1.65
electron density dependence
FE
？
0.3V
0.7V
H
0.6V
0.2V
ω1
PLE
0.5V
0.15V
0.4V
density
PL and PLE Intensity (arb.unit)
(arb. units)
BE
PL
n
0.35V
1D
ω2
0.1V
0.0V
1.564 1.568 1.572
Photon Energy (eV)
FES
1.564 1.568 1.572
Photon Energy (eV)
0.3V
L
PL and PLE Intensity (arb.unit)
(arb.
units)
Trion Binding Energy
PL
PLE
0.15V
ω1
ω2
excitation
0.1V
EB
EB ～2meV
2.33meV
2.04meV
1.97meV
1.566
1.568
1.570
Photon Energy (eV)
0.0V
PLE peak shift and PL width
PL
PLE
Peak Energy (eV)
？
1.574
1.572
1.570
ω2
Fermi Edge (70% height)
1.568
1.566
 me 

EF 1 
 mh 
ω1
1.564
Band Edge (70% height)
0.0
0.2
0.4
Voltage
0.6
0.8
Peak Energy (eV)
1.574
PL
ω1
ω2
1.5meV
1.580
1.584
1.588
Photon Energy (eV)
wire
PLE
1.572
ω2
1.570
Fermi Edge (70%)
1.568
1.566
ω1
1.564
Band Edge (70%)
0.0
Peak Energy (eV)
PL and PLE Intensity (arb.units)
wire / arm
0.2
0.4
0.6
Voltage
 me 

EF 10.8

 mh 
ω2
1.586
1.584
FE
1.582
ω1
0.2
BE
0.4
0.6
Voltage
0.8
arm
How does FES
change with EF ?
Peak shift
4
Energy (meV)
Theory
EF
2
1
EB ～2meV
0.0
0.2
0.4
0.6
0.8
Voltage
where　a  1
4
Energy (meV)
  0  　 0
 0
(ω2ｰω1)
0
((ω
12ｰω
 1)2 )  aEF  EB
Line shape

I ( )     1
3
wire
(ω2ｰω1)
arm
3
～1.5meV
EB
2
1
EF
0
0.2
0.4
0.6
Voltage
0.8
Conclusion and problems
We succeed to get electron density dependence of
1D PLE which differs from 2D PLE !!
1. Monolayer fluctuation ?
2. High electron density ?
3. Higher binding energy ?
4. Lower temperature ?
We are just doing the process of new samples !!
stage
～1.5meV
1.580
1.584
Photon Energy (eV)
PL and PLE Intensity (arb.units)
PL and PLE Intensity (arb.unit)
data
1.580
1.584
1.588
Photon Energy (eV)
data
arm
EF
wire
（meV
）
EF
（meV
）
1.8
1.1
0.8
0.5
0.2
1.580
1.584
PL and PLE Intensity (arb.units)
PL and PLE Intensity (arb.units)
1.5
1.8
1.5
1.1
0.8
0.5
0.2
1.588
Photon Energy (eV)
V. Huard et al. Phys. Rev. Lett. 84 (2000) 187
1.564 1.568 1.572 1.576
Photon Energy (eV)
PL and PLE Intensity (arb.units)
Photoluminescence Intensity (arb.unit)
Data - wire
1.5650
1.5675
Photon Energy (eV)
1.566
1.568
1.570
Photon Energy (eV)

Download Report