High efficiency AlGaAs solar cells have been demonstrated. InGaP and AlGaAs solar cells have first been grown by solid source molecular beam epitaxy (MBE) and compared. The material quality of the semiconductor layers and the design of the heterojunction have been investigated and optimized. The combination of a thick p‐AlGaAs base and a thin InGaP emitter provides a way to increase carrier mobilities and to reduce the impact of DX-centers, and leads to significant efficiency improvements. This heterojunction design has the additional advantages of a tunable bandgap of the AlGaAs absorber, and a low consumption of In. It resulted in a certified efficiency of 18.7% at a bandgap of 1.73 eV, perfectly suited for Si-based tandem devices.
This work was published online on 5 February 2020:
1.73 eV AlGaAs/InGaP heterojunction solar cell grown by MBE with 18.7% efficiency, A. Ben Slimane et al., Prog. in Photovoltaics, available online, 2019.