  Aluminum Indium Nitride (AlInN) alloys offer great potential for photovoltaic
devices thanks to their wide direct bandgap energy that covers the solar
spectrum from 0.7 eV (InN) to 6.2 eV (AlN), and their superior resistance to
high temperatures and high-energy particles. In this paper, we report the
design of AlInN on silicon heterojunctions, with the aim to explore their
potential for solar cell devices through the analysis and optimization of the
properties of the AlInN on Si heterojunction. In particular, we study the
influence of the AlInN bandgap energy, AlInN thickness and carrier
concentration, silicon surface recombination, interface defects and Si wafer
quality on the photovoltaic properties (conversion efficiency and external
quantum efficiency) of the AlInN on Si heterojunctions. The effect of
introducing an anti-reflective coating is also studied. Optimized AlInN on Si
heterostructure shows a conversion efficiency of 18% under 1-sun AM1.5G
illumination for low-quality Si wafers, which increases to 23.6% for
high-quality Si wafers and incorporating a properly designed anti-reflective
layer. In comparison with standard Si solar cells without AlInN, the external
quantum efficient of the devices increases for wavelengths below 500 nm, making
them appealing for space applications. These results lead to the AlInN on Si
heterojunction a promising future as a novel technology for solar cell devices.
