含氧空位SrTiO_3晶体电子结构研究

Study on the Electronic Structure of SrTiO_3 with Oxygen Vacancy

运用CRYSTAL-09软件计算得到了完整和含氧空位的SrTiO3晶体的电子态密度分布、能带结构和电荷密度分布。本文先通过分析完整SrTiO3晶体的电子结构,确定晶体化学键的组成。通过分析含氧空位的SrTiO3晶体的电子结构,发现禁带中出现一条新的缺陷带,缺陷带属于Σ轨道。通过缺陷能级的分析,结果表明SrTiO3晶体中2.4 eV的发光带可能是由Σ*-Σ之间的跃迁产生。

The density of states,energy bands and electron densities of both the perfect and defective（with oxygen vacancies） SrTiO3 crystal have been studied using CRYSTAL-09 code.First of all,the types of chemical bond for the perfect SrTiO3 crystal were obtained by analyzing its electronic structures.It could be seen from the electronic structures of the SrTiO3 crystal with oxygen vacancies that a new defect band occurs in the forbidden band,which belongs to the Σ orbital.The 2.4 eV luminescence band might be caused by the electron transition from Σ orbital to Σ＊ orbital.