Zn2SbN3: growth and characterization of a metastable photoactive semiconductor†
Ternary nitride semiconductors with wurtzite-derived crystal structures are an emerging class of materials for optoelectronic applications compatible with GaN and related III–V compounds. In particular, II–IV–V2 materials such as ZnSnN2 and ZnGeN2 have been very actively studied for applications in photovoltaics and light emitting devices. However, many other possible wurtzite-derived ternary nitrides have not been reported, and hence their optical and electrical properties remain unknown. Here, we report on Zn2SbN3 – the first Sb-based nitride and a photoactive semiconductor. Surprisingly, Zn2SbN3 contains Sb in the highest (5+) oxidation state, and in the unusual tetrahedral coordination. This new Zn2SbN3 material has a solar-matched 1.6–1.7 eV band gap and shows near-band-edge room-temperature photoluminescence, demonstrating its promise as an optoelectronic semiconductor. Finally, Zn2SbN3 can be synthesized at low temperature under a wide range of processing conditions, despite being metastable according to theoretical calculations. All these results, as well as the band position measurements, indicate that Zn2SbN3 is a promising emerging semiconductor for applications as an absorber in photovoltaic- and photoelectrochemical solar cells.