Effect of In$_{x}$Ga$_{1-x}$As Interlayer on Surface Morphology and Optical Properties of GaSb/InGaAs Type-II Quantum Dots Grown on InP (100) Substrates
Yu-Long Chen1,2, You Gao1, Hong Chen2**, Hui Zhang3**, Miao He1,3**, Shu-Ti Li1, Shu-Wen Zheng1
1Guangdong Engineering Research Center of Optoelectronic Functional Materials and Devices, Institute of Opto-Electronic Materials and Technology, South China Normal University, Guangzhou 510631 2Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condense Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 3College of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou 510006
Abstract：The effects of indium composition in InGaAs interlayer on morphology of GaSb/InGaAs quantum dots (QDs) and on optical properties of GaSb/InGaAs QD material system are studied. AFM images show that the change of the indium composition in InGaAs interlayer can alter the GaSb QD morphology. It is found that low indium composition in InGaAs interlayer can promote the formation of QDs, while high indium composition can inhibit the formation of QDs. The photoluminescence (PL) spectra of GaSb/InGaAs QDs at 8 K under low excitation power indicate that the third root of the excitation power is linear with the peak position, which provides a direct evidence for their luminescence belonging to type-II material optical transition. The PL spectra at 8 K under an excitation power of 90 mW show that the optical properties of GaSb/InGaAs QD material system can be affected by the indium composition in the InGaAs interlayer, and the PL peak position is linear with the indium composition. The optical properties of GaSb/InGaAs QDs can be improved by adjusting the indium composition in the InGaAs interlayer.
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2016, Vol. 33 
