K-2N双受主共掺杂P型ZnO的第一性原理研究

摘要

In this paper, we adopt the density functional theory(DFT)plane wave pseudopotential method to study the crystal structure and electronic properties for the different concentrations of the doped ZnO with K and K-2N. We show that compared with our calculated results, the band gap of the doped ZnO with K becomes wider, and that the Fermi level is less than the valence band maximum. We also find that the band gap of the codoped ZnO with K-2N becomes narrower. The codoping is an important way to improve the characteristic of p-type ZnO. On the other hand, certain changes of the optical properties of doped ZnO have taken place, I. E. , a new absorption peak happens in ZnO absorption spectrum and the new peak occurs in the imagery part of dielectric function. Static dielectric constant of the codoped ZnO with K-2N both becomes bigger.%本文采用基于第一性原理的密度泛函理论(DFT)平面波超软赝势方法,计算了未掺杂ZnO和K,K-2N掺杂ZnO体系的晶体结构、能带、电子态密度与光学性质.研究表明:K掺杂ZnO体系,带隙变宽,在费米能级附近引入了较浅的受主能级,费米能级进入到价带中.而K-2N共掺杂体系中,带隙变窄,形成了浅受主能级,这个对改善ZnO的p型掺杂有重要意义.另一方面,掺杂后ZnO的光学性质也发生了一定变化,ZnO吸收谱中出现了新的吸收峰,同时介电函数虚部都出现了新的波峰,静态介电常数ε(0)也都增大了.