Phase Stability and Defect Physics of a Ternary ZnSnN_2 Semiconductor: First Principles Insights

Direct bandgap, earth abundant semiconductors with Eg around 1.5 eV are essential for both photovoltaic and solar to fuel (photocatalytic) energy conversion. Among the conventional semiconductors, such as element Si and Ge, binary III-V (III = B, Al, Ga, In; V = N, P, As, Sb) and II-VI (II = Zn, Cd; VI = O, S, Se, Te), only a limited number of candidates have suitable bandgaps in the range 1.0–2.0 eV. This motivates the search for earth-abundant alternatives to current semiconductors for efficient, high-quality optoelectronic devices, photovoltaics and photocatalytic energy conversion. One methodology for the search is to study ternary and multi-ternary semiconductors with more elements and more flexible optoelectronic properties.