Band Gap Modification of ZnO and ZnS through Solid Solution Formation for Applications in Photocatalysis

ZnO and ZnS are both good photocatalysts, but their band gaps are too wide for efficient use under sunlight. In this work, solid solutions formed by the addition of a small amount of AlN or GaN to ZnO and AlP or GaP to ZnS are studied with first-principles calculations. Energies of mixing are low in all cases and addition of a small amount of solute can significantly reduce the band gap. Results for the different solid solutions are compared.