The effect of electronic orbital interactions on p-type doping tendency in ZnO series： First-principles calculations

The electronic structures and optical properties of B3 ZnO series of Znelectronic structures, optical properties, pseudopotential plane-wave method, \\ \hspace*{1.9cm} p-type doping tendency,electronic structures, optical properties, pseudopotential plane-wave method, \\ \hspace*{1.9cm} p-type doping tendencyProject supported by the National Natural Science Foundation of China (Grant No~10625416).2007-04-252007-06-18The electronic structures and optical properties of B3 ZnO series of Zn4X4-yMy（X ：O, S, Se or Te; M = N, Sb, C1 or I; y = 0 or 1） are studied by first-principles calculations using a pseudopotential plane-wave method. The results show that Zn d-X p orbital interactions play an important role in the p-type doping tendency in zinc-based Ⅱ-Ⅵ semiconductors. In ZnX, with increasing atomic number of X, Zn d-X p orbital interactions decrease and Zn s-X p orbital interactions increase. Additionally, substituting group-V elements for X will reduce the Zn d-X p orbital interactions while substituting group-VII elements for X will increase the Zn d-X p orbital interactions. The results also show that group-V-doped ZnX and group-Ⅷ-doped ZnX exhibit different optical behaviours due to their different orbital interaction effects.     

0～15 GPa外压下ZnO结构相变的第一性原理研究

利用第一性原理的计算方法,结合热力学和弹性力学的计算详细分析0～15 GPa外压下ZnO的结构、弹性模量和电子结构.结果表明:在研究压强范围内,B4结构的ZnO能量始终比B3结构的低,但随着外压的增加,无论是B4结构还是B3结构,都会在一定压强下转变成B1结构.B4至B1的压强转变点为12.4 GPa,B3至B1的压强转变点是11.8 GPa.B4结构转变成B1结构的瞬间,体系体积缩小约17%.结果与已有的实验与理论结果相符.B4结构的ZnO剪切模量在6～8 GPa时急剧下降,与已有的实验和理论计算结果相符.电子结构特征表明,随着外压的增强,体系中Zn 3d电子与O 2p电子相互作用减弱.