稀土（Ce,Gd）掺杂CdS的第一性原理研究
First principle study on CdS with doping rare earth(Ce，Gd)

采用第一性原理赝势平面波法中的LDA+U的方法对稀土(Ce,Gd)掺杂CdS的光电性质进行了计算与分析. 结果表明: Ce, Gd掺杂后, CdS的晶格常数增大, 费米面附近的能带明显增多、变密, 禁带宽度有所增大. Ce和Gd的f态的强局域性使体系产生磁有序性. 稀土掺杂后CdS的静态介电常数增大而反射率明显降低. 以上结果表明稀土元素的掺入能有效调制CdS的光电性质.
By using the local density approximation with Hubbard-U corrections method of the first principle pseudo-potential plane-wave method, the photoelectric properties of CdS doped with rare earth(Ce,Gd) are calculated and analyzed. The calculation results show that: after doping Ce or Gd, the lattice constants increase. The number of energy bands near the Fermi surface increases and becomes dense obviously, and the band gap widens. The strong locality of the f electron states for Ce and Gd makes the system produce magnetic ordering. After doping rare earth, the static dielectric constant increases and reflectivity decreases significantly. These results indicate that rare earth can effectively modulate the photoelectric properties of CdS.