Efficiency enhancement in InAs/GaAsSb quantum dot solar cells with GaP strain compensation layer
- Division of Industrial Metrology, Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of)
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)
The structural characteristics and device performance of strain-compensated InAs/GaAsSb quantum dot solar cells (QDSCs) with different GaP coverages have been studied. The in-plane (out-of-plane) compressive strain of the QD stacks is reduced from −1.24 (+1.06) to −0.39 (+0.33)% by increasing the GaP coverage from 0 to 4 ML. This strain compensation decreases strain-induced dislocation density and hence enhances the overall crystal quality of the QDSCs. The external quantum efficiency spectra reveal that the increase in the GaP coverage increases the photocurrent from wavelengths shorter than GaAs bandedge of 880 nm, while it decreases the photocurrent from near infrared wavelengths beyond the bandedge. The conversion efficiency of the QDSCs is significantly improved from 7.22 to 9.67% as the GaP coverage is increased from 0 to 4 ML.
- OSTI ID:
- 22591420
- Journal Information:
- Applied Physics Letters, Vol. 108, Issue 10; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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