Hf、N以不同比例掺杂ZnO的第一性原理计算

First-principles study on (Hf,N)-codoped ZnO with different proportions

基于第一性原理密度泛函理论,计算分析了Hf、N以不同掺杂比例掺杂ZnO(Zn_(16)O_(16))形成Zn_(15)O_(16-x_HfN_x(x=1,2,3,4)体系的结构参数、电子结构、Mulliken电荷布居和光学方面的性质.计算结果表明,掺杂体系晶胞体积不同程度增大;x=1时体系的费米能级上移进入导带使其呈现n型半导体特征,吸收峰和反射峰红移较小,尤其是反射峰,主要表现为强度的变化;但x=2,3,4体系的费米能级均在价带顶附近,且随掺杂比例的增大,掺杂体系的费米能级进入价带的深度逐渐增大,N 2p态的贡献作用也越来越显著,使掺杂体系呈现p型半导体特征,吸收峰和反射峰均有较大的红移,这将有利于ZnO体系在可见光领域的应用.

The properties of the crystal structure, electronic structure, Mulliken Charge population and optical properties of the system of Hf and N co-doped ZnO （Zn15O16-xHfNx x=1,2,3,4） are calculated by the first-principles based upon the density function theory （DFT）. We get some computational conclusions, such as the sizes of co-doped systems unit cell volume are bigger than undoped one’s; when the x is equal to 1, the Femi energy level of the system moves up, and moves through the conduction band, all this demonstrates the matter is n-type semiconductor, and the Redshifts of absorption peak and reflection peak of the system are less; When the x is equal to 2, 3, or 4, the Femi energy levels of the co-doped system Zn15O16-xHfNx are a little lower than valence-band maximum, with the doping ratio increasing, the depth of the Femi energy level under valence-band maximum is gradually increasing, the contribution of 2p state of N element is more and more outstanding, which indicates the matter is p-type semiconductor, and its Redshifts of absorption peak and reflection peak are big. As a result, all the properties widen the application of co-doped ZnO in visible light field.