A First-Principles Investigation on Microscopic Atom Distribution and Configuration-Averaged Properties in Cd_1-xZn_xS Solid Solutions

The structural, energetic, and electronic properties of zincblende and wurtzite phase Cd_1-xZn_xS (0≤x≤1) solid solutions were investigated by first-principles calculations. It was revealed that the trend of atom distribution in configurations with the same x value can be quantitatively characterized by the average length of the Zn¯S bonds. The origin of this trend was attributed to the strong interaction of the Zn¯S bonds, which acted against the aggregation of Zn atoms in this solid solution. By using a configuration-averaged method, structural and energetic properties were estimated as a function of Zn content at the level of the generalized gradient approximation, whereas electronic properties were corrected by using a hybrid functional. Phase diagrams of both solid solutions were established. An optimal x value of approximately 0.5 for photocatalytic hydrogen production was determined by taking both the band edges and band gaps into consideration; this conclusion was supported by the results of a variety of experiments.