A straightforward one-pot approach to two new defect energy levels in ZnS

In this study, for the first time, we report a straightforward one-pot method to obtain ZnS with multiple vacancies (V+V--ZnS). It is found that two new defect energy levels are formed by Zn vacancies and S vacancies, which are close to the valence band (VB) top and conduction band (CB) bottom, respectively. The newly formed energy levels in V+V--ZnS greatly enhance light absorption: 480 nm and 2.44 eV (V+V--ZnS) vs. 399 nm and 3.24 eV (ZnS). Moreover, V+V--ZnS exhibits an evidently improved charge separation efficiency. Thus, V+V--ZnS shows a high visible-light activity, while ZnS has no response to visible light. This method is simple, and could be extended to mass production.

Automated summary

In this study, a straightforward one-pot method was used to obtain ZnS with multiple vacancies (V+V--ZnS) for the first time. Newly formed energy levels in V+V--ZnS greatly enhance light absorption and exhibit improved charge separation efficiency compared to ZnS, making V+V--ZnS highly active under visible light. This simple method could be extended to mass production.