Sb-Na共掺p型ZnO的第一性原理研究

First-principles Study of p-type ZnO Codoped with Sb-Na

运用密度泛函理论,计算了SbZn、NaZn、SbZn-n NaZn掺杂ZnO晶体的稳定性、能带结构和电子态密度.研究发现SbZn、NaZn、SbZn-n NaZn掺杂ZnO晶体的结构稳定,Sb-Na共掺杂改善了体系的固溶度。能带结构表明,SbZn体系为n型间接带隙半导体材料;NaZn、SbZn-2NaZn体系为p型半导体材料;SbZn-NaZn、SbZn-3NaZn体系为本征半导体材料.对p型半导体材料体系的导电性能研究发现,SbZn-2NaZn体系电导率大于NaZn体系的电导率,即SbZn-2NaZn掺杂改善了体系的导电性.计算结果为实验制备p型ZnO材料提供了理论指导。

The formation energy, electronic structures of Sb-Na codoping in ZnO were calculated by the first-principles method based on the density functional theory. The calculated results show that Sbzn has the highest formation energy than any other complexes under equilibrium conditions. The SbZn-2NZn,1 and Sbzn-3Nazn systems have smaller formation energy than other complexes, indicating that the formation of Sbzn-2Nazn and Sbzn-3Nazn may be easier. The band structure shows that the Nazn system is a p-type direct-band-gap semiconductor material and the calculated band gap （0.84 eV） is larger than ZnO. The Sbzn system is an n-type semiconductor material with an indirect band gap of 0.72 eV. The Sbz,-2Nazn is also a p-type semiconductor material and the indirect band gap is 0.62 eV. The Sbzn-Nazn and Sbzn- 3Nazn are intrinsic semiconductor materials and the band gap are 0.78 eV and 0.53 eV, respectively. The influence of Sb-Na codoping in ZnO on p-type conductivity is also discussed. The electrical conductivity of Sbzn-2Nazn is larger than that of Nazn, meaning the hole in Sbzn-2Nazn system has a better carrier transfer character. We inferred that Sbzn-2Nazn should be a candidate of p-type conduction.