D. Ding, J.-B. Wang, S. R. Johnson, S.-Q. Yu, Y.-H. Zhang
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Transcript of D. Ding, J.-B. Wang, S. R. Johnson, S.-Q. Yu, Y.-H. Zhang
MBE Optoelectronics Group
Determination of internal quantum efficiency in semiconductors suitable for
luminescence refrigeration
D. Ding, J.-B. Wang, S. R. Johnson, S.-Q. Yu, Y.-H. Zhang
Center for Semiconductor Optical Refrigeration Department of Electrical Engineering
Arizona State University
MBE Optoelectronics Group
Sample Design
MBE Optoelectronics Group
Modeling
2'2 NBmL
2'11 NBANm
NmP
s
sin
b N
hdr
AP
2
drTTNBL sce 22'
LLmB
A
m
mP 2/1
22/12
1
LLMMP 2/121
22/122
11 , m
B
AM
m
mM LLM
L
NBAN
NBi
2/1
22'
2'
2
'
/
1
BN
Nnc
BB
phr
r
MBE Optoelectronics Group
Model fitting
MBE Optoelectronics Group
Internal quantum efficiency
MBE Optoelectronics Group
Determination of N, A and ΔF
1
12 M
mm
2'1 NBANmP
b
in
A
hdrm
2
1
22/122
11 , m
B
AM
m
mM
2
2
' m
M
B
A
inb hdrA , , ,
2
1
2
2
2
2
22' 44
1
m
P
m
M
m
MNB r
NBBN
1
2'2
r
232
12
kT
E
mm
h
c
nB g
g
he
g
B
BNN
22
vcg NN
NkTkTEF
2
ln kTkTgEF
vc eNN/
rBm
MA 1
2
2
MBE Optoelectronics Group
Internal quantum efficiency vs. ΔF
MBE Optoelectronics Group
Comparison of with and without surfactant
MBE Optoelectronics Group
InGaAs QWs
MBE Optoelectronics Group
Summary
• A power and temperature dependent PL measurement is proposed to determine the internal quantum efficiency and recombination coefficients
• A set of samples are designed to give almost same absorption for the pumping laser light (He-Ne)
• The recycling factor of slab structure is modeled and numerical calculated for various thicknesses
• 98.5% internal quantum efficiency is determined for GaAs at 100 K with ΔF = -3.5 kT
• The SRH recombination coefficient is determined to be around 2 ~ 7 x 106 /s at a temperature range from 50 K to 200 K
• The SRH recombination coefficient is related to the barrier thickness and the surfactant will decrease the SRH recombination