Exploring the stable structures and photovoltaic properties of an ideal pseudo-binary alloy: Indium gallium phosphide

Abstract

Pseudo-binary III-V semiconductor alloys are promising for applications in optical, photovoltaic and photoelectrochemical fields, for their tunable band gaps and band alignments. In this work, we carefully investigate structural and photovoltaic properties of indium gallium phosphide (InxGa1-xP; 0 < x < 1) alloys. Using evolutionary algorithm crystal structure prediction, we perform structure searches for indentifying potential crystal structures of InxGa1-xP alloys in nine chemical compositions at zero temperature and ambient pressure. We find that InxGa1-xP alloys can adopt zinc blende (ZB) and wurtzite (WT) structures and the former generally have lower energy than the latter at all compositions. Based on these predicted InxGa1-xP structures, we evaluated their spectroscopic limited maximum efficiencies (SLMEs) and find that InxGa1-xP alloys with high In concentrations (x ≥ 0.5) have higher SLME values than those of InxGa1-xP alloys with low In concentrations (x < 0.5). We also find that SLMEs of disordered InxGa1-xP alloys are larger than those of ordered alloys due to the enhanced oscillator strengths.