C和F掺杂p型ZnO的第一性原理研究

First-principles Study of p-type ZnO Doped by C and F

采用基于密度泛函理论的第一性原理计算方法对C/F单掺杂ZnO和C-F共掺杂ZnO的O位体系进行了研究,讨论了掺杂体系的稳定性、电子结构和电学性质、光学性质。研究结果表明C和F共掺的形成能比C单掺的形成能小很多,即C和F共掺增加了体系的稳定性;计算获得的电导率之比分别为σ_(C-ZnO)/σ_(ZnO)=9.45,σF-ZnO/σ_(ZnO)=6.78,σ_(C-F-ZnO)/σ_(ZnO)=19.62,显然,C和F共掺杂对ZnO体系的电导率增强效果最明显;载流子迁移率之比μ_(C-ZnO)/μ_(ZnO)=1.67,μF-ZnO/μ_(ZnO)=2.31,μ_(C-F-ZnO/)μ_(ZnO)=2.50,说明C和F共掺增加了载流子迁移率。综合电导率和载流子迁移率二者结果,可认为C和F共掺极大地提高了ZnO的导电性。ZnO掺杂体系在可见光波长范围内透射率大于95%,具有良好的透光性。计算结果为实验上制备p型透明导电ZnO材料提供了理论指导。

In the paper, the stability, electronic structures, electrical and optical properties of p-type zinc oxide （ZnO） and C/F doped or C-F codoped ZnO systems have been studied, based on the density functional theory of the first-principles calculation method. The results show that the formation energy of C-F codoped ZnO systems are smaller than the C doped ZnO systems, so the C-F codoping method can enhance the stability of the materials. The ratio of electrical conductivity are ac.Zn0/aZn0 =9.45, aF.Zn0/ aZn0 = 6. 78, ac.F.Zn0/aZn0 = 19. 62, which shows that the C-F codoping ZnO systems can enhance the electrical conductivity. Forthermore, the ratio of carrier mobility are ｜JLc.Zn0/｜JLZn0 = 1.67 , jjiF.Zn0/｜JLZn0 = 2.31, iJic-F-znO^l^znO =2.50, so the codoping method also can enhance the electrical properties. On the other hand, the transmission index of doped systems are higher than 95% in the visible light range, which shows that C/F doped and C-F codoped ZnO have good optical properties. These calculated results provide theoretical guidance for the experimental prepared pure p-type ZnO with good electrical and optical properties.