Electronic and optical properties of several cluster-assembled materials based on Zn12O12: a first-principles study

Based on the first-principles calculations, we systematically studied and fully characterized the electronic structure and optical properties of four novel ZnO phases assembled by Zn₁₂O₁₂ clusters and compared them with the results of wurtzite (WZ) ZnO. The results show that the density of states of the four cluster-assembled materials is similar to that of WZ-ZnO, but the bandgap is larger than that of the latter. Among them, FAU-ZnO, LTA-ZnO, and SOD-ZnO are direct bandgap semiconductors. The calculation of the optical properties of SOD-ZnO is most similar to those of WZ-ZnO, but R-ZnO has higher static permittivity, reflection, and refraction coefficients. Considering that the presence of cage-like voids in cluster-assembled materials is more conducive to doping of various elements, cluster-assembled materials are more likely to change the bandgap and corresponding electronic structure through doping than WZ-ZnO. From this perspective, these two materials have great potential for photocatalytic and optoelectronic device applications.