InAlAs photovoltaic cell design for high device efficiency

This study presents a new design for a single‐junction InAlAs solar cell, which reduces parasitic absorption losses from the low band‐gap contact layer while maintaining a functional window layer by integrating a selective etch stop. The etch stop is then removed prior to depositing an anti‐reflective coating. The final cell had a 17.9% efficiency under 1‐sun AM1.5 with an anti‐reflective coating. Minority carrier diffusion lengths were extracted from external quantum efficiency data using physics‐based device simulation software yielding 170 nm in the n‐type emitter and 4.6 μm in the p‐type base, which is more than four times the diffusion length previously reported for a p‐type InAlAs base. This report represents significant progress towards a high‐performance InAlAs top cell for a triple‐junction design lattice‐matched to InP. Copyright © 2017 John Wiley & Sons, Ltd. This study presents a new design for a single‐junction InAIAs solar cell. The design reduces absorption losses from the low band‐gap contact layer and preserves window integrity by integrating an etch stop, which is removed before anti‐reflective coating deposition. The final cell had a 17.9% efficiency under 1‐sun AM1.5 with an anti‐reflective coating. This represents a significant improvement over existing reports of single‐junction InAIAs cells to date.