Abstract
High-efficiency solar cells are essential for high-density terrestrial applications, as well as space and potentially vehicle applications. The optimum bandgap for the terrestrial spectrum lies beyond the absorption range of a traditional dual junction GaInP/GaAs cell, with the bottom GaAs cell having higher bandgap energy than necessary. Lower energy bandgaps can be achieved with multiple quantum wells (QWs), but such a pathway requires advanced management of the epitaxial growth conditions in order to be useful. Strain-balanced GaAsP/GaInAs QWs are incorporated into a single junction GaAs solar cell and a dual junction GaInP/GaAs solar cell, leading to 27.2% efficiency in the single junction device and a one-sun record 32.9% efficiency in the tandem device. Good carrier collection and low non-radiative recombination are observed in the cells with up to 80 QWs. The GaAs cells employ a rear-heterojunction architecture to boost the open-circuit voltage to over 1.04 V in the quantum well device, despite the large number of QWs.
Original language | American English |
---|---|
Article number | 2002874 |
Number of pages | 8 |
Journal | Advanced Energy Materials |
Volume | 11 |
Issue number | 4 |
DOIs | |
State | Published - 2021 |
Bibliographical note
Publisher Copyright:© 2020 Wiley-VCH GmbH
NREL Publication Number
- NREL/JA-5900-77777
Keywords
- III-V
- photovoltaic
- quantum wells
- solar cell efficiency
- strain-balancing
- tandem