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