Easily doped p-type, low hole effective mass, transparent oxides

TL;DR

This study identifies four oxides with high transparency, low hole effective mass, and stable p-type doping potential, advancing the development of transparent electronics.

Contribution

It introduces four novel oxides with excellent properties for transparent p-type semiconductors, identified through high-throughput first-principles calculations.

Findings

La2SeO2 can be doped p-type with Na impurities

The oxides have direct band gaps >3.1 eV

They exhibit low hole effective mass

Abstract

Fulfillment of the promise of transparent electronics has been hindered until now largely by the lack of semiconductors that can be doped p-type in a stable way, and that at the same time present high hole mobility and are highly transparent in the visible spectrum. Here, a high-throughput study based on first-principles methods reveals four oxides, namely X2SeO2, with X = La, Pr, Nd, and Gd, which are unique in that they exhibit excellent characteristics for transparent electronic device applications-i.e., a direct band gap larger than 3.1 eV, an average hole effective mass below the electron rest mass, and good p-type dopability. Furthermore, for La2SeO2 it is explicitly shown that Na impurities substituting La are shallow acceptors in moderate to strong anion-rich growth conditions, with low formation energy, and that they will not be compensated by anion vacancies VO or VSe.