稀土掺杂CdTe太阳电池背接触层ZnTe的第一性原理研究

First principles study of rare earth doped in ZnTe used for CdTe solar cell back contact layer

结合CdS/CdTe太阳电池背接触层的制备要求考虑,利用基于密度泛函理论平面波超软赝势方法和广义梯度近似,计算了未掺杂ZnTe、稀土Y、Gd掺杂ZnTe的能带和电子态密度,得到了不同体系下系统总能和晶格常数.研究表明,稀土Y和Gd掺杂后ZnTe结构的稳定性均提高,掺杂Y使ZnTe与CdTe的晶格匹配更好.计算表明,掺杂可使载流子发生简并,掺Y比掺Gd电子有效质量小,掺Y与掺Gd的载流子浓度数量级相同.根据计算结果分析了稀土掺杂对ZnTe背接触层的影响.

In consideration of the preparation of CdS/CdTe solar cell back contact layer,the band structure and the density of states of undoped and（Y,Gd） doped in ZnTe were caculated from the plane wave ultra soft pseudo potential method based on density functional theory and generalized gradient approximation.We acquired the system total energy and lattice parameter.As a result,the structural stability improve after doping,the lattice match between ZnTe and CdTe are better when Y doped.（Y,Gd） doped make the ZnTe semiconductor degeneration.Compared with Gd,the electronic effective mass of ZnTe doped with Y are lighter.The carrier concentration order of magnitude in different doping system are same.We analysed the influence on ZnTe used for back contact layer when doped with（Y,Gd）.