中国物理B ›› 2021, Vol. 30 ›› Issue (1): 17802-.doi: 10.1088/1674-1056/abb309

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  • 收稿日期:2020-06-28 修回日期:2020-08-19 接受日期:2020-08-27 出版日期:2020-12-17 发布日期:2020-12-23

Effect of Sb composition on the band alignment of InAs/GaAsSb quantum dots

Guangze Lu(陆光泽)1,2, Zunren Lv(吕尊仁)1, Zhongkai Zhang(张中恺)1,2, Xiaoguang Yang(杨晓光)1,2,†, and Tao Yang(杨涛)1,2   

  1. 1 Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China; 2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-06-28 Revised:2020-08-19 Accepted:2020-08-27 Online:2020-12-17 Published:2020-12-23
  • Contact: †Corresponding author. E-mail: xgyang@semi.ac.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2019YFB1503601 and 2017YFB0405302), the National Natural Science Foundation of China (Grant Nos. 61574139 and U1738114), and the Strategic Priority Research Program on Space Science, the Chinese Academy of Sciences (Grant No. XDA15051200).

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Abstract: Aiming to achieve InAs quantum dots (QDs) with a long carrier lifetime, the effects of Sb component in cap layers on the band alignment of the InAs/GaAsSb QDs have been studied. InAs QDs with high density and uniformity have been grown by molecular beam epitaxy. With increasing Sb composition, the InAs/GaAsSb QDs exhibit a significant red-shift and broadening photoluminescence (PL). With a high Sb component of 22%, the longest wavelength emission of the InAs/GaAs0.78Sb0.22 QDs occurs at 1.5 μ m at room temperature. The power-dependence PL measurements indicate that with a low Sb component of 14%, the InAs/GaAs0.86Sb0.14 QDs have a type-I and a type-II carrier recombination processes, respectively. With a high Sb component of 22%, the InAs/GaAs0.78Sb0.22 QDs have a pure type-II band alignment, with three type-II carrier recombination processes. Extracted from time-resolved PL decay traces, the carrier lifetime of the InAs/GaAs0.78Sb0.22 QDs reaches 16.86 ns, which is much longer than that of the InAs/GaAs0.86Sb0.14 QDs (2.07 ns). These results obtained here are meaningful to realize high conversion efficiency intermediate-band QD solar cells and other opto-electronic device.

Key words: quantum dots, type-II band alignment, intermediate-band solar cell, molecular beam epitaxy

中图分类号:  (Quantum dots)

  • 78.67.Hc
78.66.Fd (III-V semiconductors) 78.67.-n (Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures)