Ordered-Vacancy Chalcogenides—New N-Type Dopable Diamond-Like Semiconductors with High Thermoelectric Performance

Doping remains a bottleneck in discovering novel materials for functional applications such as thermoelectrics (TE) and photovoltaics. Diamond-like semiconductors (DLS), which have recently garnered interest to be used as potential TE materials, suffer from doping asymmetry. That is, most well-known DLS phases with moderate carrier concentrations are native p-type semiconductors due to self-doping, and are often resistant to n-type doping. However, computational predictions indicate that superior TE performance can be realized through n-type doping. In this work, we show that ordered-vacancy chalcogenides (OVC) are promising n-type dopable DLS with unique ordered vacancy structures. We first apply chemical replacements on three OVC structural prototypes to generate new plausible compounds. Using first-principles calculations, the plausible compounds are then computationally assessed for their stability, TE performance, transport properties, dopability, and achievable carrier concentrations. Utilizing this computational workflow, we identify several stable OVCs with high TE performance that are amenable to n-type doping. This comprehensive computational analysis for OVCs provides insights for understanding doping asymmetry in DLS, and may be used to guide experimental search for dopable semiconductors.