Author(s): Lu, GZ (Lu, Guangze); Lv, ZR (Lv, Zunren); Zhang, ZK (Zhang, Zhongkai); Yang, XG (Yang, Xiaoguang); Yang, T (Yang, Tao)

Source: CHINESE PHYSICS B Volume: 30 Issue: 1 Article Number: 017802 DOI: 10.1088/1674-1056/abb309 Published: JAN 2021

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 mu 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.

Accession Number: WOS:000607311200001

ISSN: 1674-1056

eISSN: 1741-4199

Full Text: https://iopscience.iop.org/article/10.1088/1674-1056/abb309