Band engineering of wurtzite-derived semiconductors Cu2ZnSiS4 and Cu2ZnSiSe4

The electronic and optical properties of Cu2ZnSiS4 and Cu2ZnSiSe4 in wurtzite-kesterite and wurtzite-stannite structures are studied using first-principles calculations. Optical transitions at high symmetry points between valence bands and conduction bands are discussed. Band structures are presented to analyze other properties. Optical constants and dielectric function spectra are obtained as well, and the variations in the calculated properties between different compounds and structures are discussed in detail by comparing to available experiments.