Controlling electronic structure of single-layered HfX3 (X=S, Se) trichalcogenides through systematic Zr doping.

The electronic structures of Hf 1 - x Zr x S 3 and Hf 1 - x Zr x Se 3 trichalcogenides are investigated by first-principles calculation. In particular, step change of Zr concentration is intensively investigated. Our calculations reveal that doping of Zr atoms increase the strength of cohesion between the atoms in HfX 3 (X = S, Se) monolayers, and results in occurring of energetically more stable alloys. In addition, doping of Zr atoms in HfS 3 causes band gap bowing, which means the curve of band gap values shows quadratic nonlinearities while change from semimetal to semiconductor is observed in HfSe 3 case. The examined band structures indicate that Hf 1 - x Zr x S 3 monolayers have very suitable band gap values for water splitting and also their band edge potentials have sufficiently higher or lower positions than the required potential values for the reduction or oxidation potentials. [ABSTRACT FROM AUTHOR]