ZnO(110)单层膜对O的自吸附及其电子结构的研究

基于密度泛函理论方法研究分析了一种Zn顶位吸附O的ZnO(110)-O二维膜材料的结构、结合性质、磁性质、电子结构和光吸收性质。结果表明,ZnO(110)二维膜经过O吸附之后,Zn-O键长分别增大到0.1992nm和0.1973nm,Zn-O链之间的距离减小到0.5628nm,O-Zn-O键角度为108.044°,ZnO(110)膜Zn顶位对O原子的吸附为倾斜的吸附。经过Zn顶位O的吸附,ZnO(110)二维膜内原子间离子性结合性增强,吸附的O与Zn也形成偏离子性结合键,Zn顶位吸附O原子之后能量有所降低,吸附体系为反铁磁性材料。O吸附的ZnO(110)-O二维膜为间接带隙型材料,带隙宽度为0.565eV。材料中的p电子对费米能处态密度贡献较多。ZnO(110)-O二维膜最高吸收峰位于156nm,吸收率为67181光吸收单位,其在445nm以上具有宽的强吸收带。

Absorption on O and Electronic Structure Properties of Single Layer ZnO ( 110 ) Thin Film

The geometical structure,combination,magnetism,electronic structure and the optical absorption properties of one kind of oxygen absorbed 2 dimentional ZnO(110) film at Zn top position are studied by density funtional theory analyzing method. The results show that the Zn-O bond length is increased to 0.1992 nm and 0.1973 nm,the distance between Zn-O chains is decreased to 0.5628 nm,the O-Zn-O bond angle is 108.044°,and the O absorption on Zn top position is inclined. The ionic combination between Zn and O is strengthened by O absorption on Zn top position,the combination between absorbed O and Zn is also ionic. The total energy is lowered by O absorption,the oxygen absorbed ZnO(110)-O is antiferromagnetic type material. The oxygen absorbed ZnO(110)-O is indirect band gap material with energy gap of 0.565 eV. The p type electrons contribute to density of state most at Fermi energy. The oxygen absorbed ZnO(110)-O has an absorption peak at 156 nm with absorption unit of 67181,it has a wide absorption band above 445 nm.