Al,Ga掺杂ZnO电子结构和光电特性的第一性原理计算  

First-principles calculation of electronic structure and optical properties of Al,Ga doped ZnO

作　　者：王天兴[1,2] 李苗苗[1,2] 宋桂林[1,2] 常方高[1,2] 

机构地区：[1]河南师范大学物理与信息工程学院,新乡453007 [2]河南省光伏材料重点实验室,新乡453007

出　　处：《原子与分子物理学报》2011年第6期1130-1136,共7页Journal of Atomic and Molecular Physics

基　　金：河南省重大科技攻关项目(092102210018);河南省教育厅自然科学研究计划项目(2010B140008;2011A140016);河南师范大学青年科研基金(2010qk02)

摘　　要：采用基于密度泛函理论(DFT)框架下广义梯度近似(GGA)的PBE平面波超软赝势方法,计算了本征ZnO,Al掺杂ZnO(ZnAlO)和Ga掺杂ZnO(ZnGaO)的能带结构、态密度、复介电函数和复电导率.其中Al或Ga是以替位杂质的形式进入ZnO晶格.计算结果表明纤锌矿型ZnO,ZnAlO和ZnGaO都是直接带隙半导体材料,掺杂后ZnO的带隙变小,且ZnAlO的带隙略大于ZnGaO.掺杂后ZnO)的电子结构发生变化,费米能级由本征态时位于价带顶上移进入导带,ZnO表现为n型掺杂半导体材料,掺杂后在导带底出现大量由掺杂原子贡献的自由载流子—电子,明显提高了电导率和介电函数,改善了ZnO的导电性能,并且ZnAlO的导电性能要略好于ZnGaO.We present the structural and electronic characterization of n-doped （Aluminium or Gallium） ZnO and the effect of the doping on the calculated optical properties. The fully-relaxed calculations have been made using the density functional theory （DFT） with generalized gradient approximation （GGA）. Our results show that the wurtzite ZnA10 and ZnGaO are still direct band gap semiconductors as ZnO. And the ZnA10 has a slightly larger band gap than that of ZnGaO. With doping, the A1 or Ga-donor lev- els appearing in the conduction band hybridize with the Oxygen-2p states and help decrease the resistivi- ty of these doped systems as was found experimentally. The calculated optical properties show a small enhancement in the intensity close to the conduction band as a result of these A1 or Ga levels. And the ZnA10 has a higher conductivity than ZnGaO.

关 键 词：ZnO N型掺杂 密度泛函 光学特性 

分 类 号：O471[理学—半导体物理]