Effect of natural non-metallic impurities on the electronic structure and optical properties of sphalerite ZnS

Abstract

Impurity-bearing sphalerite is widely found in nature and plays a vital role in photocatalysis. A systematic theoretical study of the crystal structure, band gap and optical properties of ZnS containing Si, Se and P impurities, respectively, is carried out using density functional theory calculations. The results show that non-metallic atoms in the interstices narrow the ZnS bandgap, improving the electrical conductivity of sphalerite. Analysis of the optical properties reveals that ZnS containing non-metallic impurities produces light absorption at higher energies. Meanwhile, the presence of all three impurities leads to a red shift in the absorption band edge of ZnS, which favors the extension of the light absorption range of sphalerite. The effect of the Si impurity is greater than that of the remaining two impurities, with the highest red shift. This research contributes to the application of sphalerite (ZnS) containing natural impurities in the field of new luminescent materials.