Gallium-Boron-Phosphide (GaBP$_2$): A New III-V Semiconductor for photovoltaics

TL;DR

This paper reports the discovery of Gallium-Boron-Phosphide (GaBP₂), a new stable, non-toxic III-V semiconductor with an optimal bandgap for high-efficiency photovoltaics, validated through machine learning and ab-initio simulations.

Contribution

The study introduces GaBP₂ as a novel photovoltaic material and demonstrates ML and DFT methods for predicting and validating its properties, including bandgap and stability.

Findings

GaBP₂ has a bandgap of 1.65 eV close to the ideal for photovoltaics.

GaBP₂ is thermally, dynamically, and mechanically stable.

ML can predict bandgaps with RMSE less than 0.4 eV for related semiconductors.

Abstract

Using machine learning (ML) approach, we unearthed a new III-V semiconducting material having an optimal bandgap for high efficient photovoltaics with the chemical composition of Gallium-Boron-Phosphide(GaBP$_2$, space group: Pna2$_1$). ML predictions are further validated by state of the art ab-initio density functional theory (DFT) simulations. The stoichiometric Heyd-Scuseria-Ernzerhof (HSE) bandgap of GaBP$_2$ is noted to 1.65 eV, a close ideal value (1.4-1.5 eV) to reach the theoretical Queisser-Shockley limit. The calculated electron mobility is similar to that of silicon. Unlike perovskites, the newly discovered material is thermally, dynamically and mechanically stable. Above all the chemical composition of GaBP$_2$ are non-toxic and relatively earth-abundant, making it a new generation of PV material. Using ML, we show that with a minimal set of features the bandgap of III-III-V and II-IV-V semiconductor can be predicted up to an RMSE of less than 0.4 eV. We presented a set of scaling laws, which can be used to estimate the bandgap of new III-III-V and II-IV-V semiconductor, with three different crystal phases, within an RMSE of approx. 0.5 eV.