Indium phosphide solar cells made by ion implantation

Abstract

High-efficiency indium phosphide solar cells of the shallow homojunction type have been made using ion implantation to form the emitter layer. An anneal in phosphine was used to recover the implant damage. The cells show a 5% higher short-circuit current than cells with a similar base but with an epitaxial emitter. The open-circuit voltage is slightly higher than that of the epitaxial cells, and the fill factor slightly lower. Conversion efficiency of 18.8% (air mass zero, total area) has been achieved; this is the highest thus far reported for an InP cell.