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Enhancement of minority carrier lifetime of GaInP with lateral composition modulation structure grown by molecular beam epitaxy

Authors :
Y.T. Lee
Hyeong-Yong Hwang
Chang Young Park
Kwangwook Park
Sooraj Ravindran
Young-Dahl Jho
Seokjin Kang
Bong-Joong Kim
Yong-Ryun Jo
Source :
Journal of Applied Physics. 116:043516
Publication Year :
2014
Publisher :
AIP Publishing, 2014.

Abstract

We report the enhancement of the minority carrier lifetime of GaInP with a lateral composition modulated (LCM) structure grown using molecular beam epitaxy (MBE). The structural and optical properties of the grown samples are studied by transmission electron microscopy and photoluminescence, which reveal the formation of vertically aligned bright and dark slabs corresponding to Ga-rich and In-rich GaInP regions, respectively, with good crystal quality. With the decrease of V/III ratio during LCM GaInP growth, it is seen that the band gap of LCM GaInP is reduced, while the PL intensity remains high and is comparable to that of bulk GaInP. We also investigate the minority carrier lifetime of LCM structures made with different flux ratios. It is found that the minority carrier lifetime of LCM GaInP is ∼37 times larger than that of bulk GaInP material, due to the spatial separation of electrons and holes by In-rich and Ga-rich regions of the LCM GaInP, respectively. We further demonstrate that the minority carrier lifetime of the grown LCM GaInP structures can easily be tuned by simply adjusting the V/III flux ratio during MBE growth, providing a simple yet powerful technique to tailor the electrical and optical properties at will. The exceptionally high carrier lifetime and the reduced band gap of LCM GaInP make them a highly attractive candidate for forming the top cell of multi-junction solar cells and can enhance their efficiency, and also make them suitable for other optoelectronics devices, such as photodetectors, where longer carrier lifetime is beneficial.

Details

ISSN :
10897550 and 00218979
Volume :
116
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi...........1662bd6f6df01348a76102216f7ca9b4
Full Text :
https://doi.org/10.1063/1.4891462