Magnetic and electronic structure properties of Co-doped SnO2 nanoparticles synthesized by the sol-gelhydrothermal technique

No abstract

No abstract

The effect of S/Se/Te-doped ZnO system on photocatalytic performance has been extensively studied. However, theoretical computational studies on S/Se/Te-doped ZnO systems containing O or Zn vacancies are lacking. Previous theoretical computational studies have also ignored the problem of unintentional introduction of H-interstitial impurities in the semiconductor fabrication process in a vacuum environment. In this paper, first-principle study is used to investigate S/Se/Te-doping and the vacancy (VO or VZn) and H gap coexistence on the photocatalytic properties of ZnO. The results showed that the Zn35SHiO35 system has the best hole life, strong activity, obvious red shift of absorption spectrum, and strong oxidation reaction. This has good theoretical reference value to be used as a photocatalyst for oxidative reaction to decompose water to produce H2.

In a vacuum environment, when ZnO is prepared using the chemical vapor deposition method and the molecular beam epitaxial growth method, H-gap impurities inevitably remain in the ZnO system, which is often ignored. The study of Zn vacancies under experimental conditions poses a challenge. Second, as an n-type semiconductor, ZnO is characterized by a self-compensation of natural donor defects and poor stability, which severely limit the acquisition of p-type ZnO. Based on the above problems, the conductive properties of S/Se/Te doped and VZn-Hi coexisting ZnO were investigated by first principle to acquire high-stability and high-quality p-ZnO. The study found that Zn35SO35, Zn35SeO35, and Zn35SHiO35 all have good p-type conductivity, which can effectively improve hole mobility and electrical conductivity. Among them, Zn35SO35 has the largest hole concentration at 2.80×1021 cm−3, as well as the best conductivity. The choice of Zn35SO35 provides a reference for obtaining new high-quality p-type ZnO semiconductors.