Co-Mo共掺杂Al2O3电子结构及透射率的第一性原理计算

First-principles calculation on the electronic structures and optical transmittance of Al2O3 codoped with Co-Mo

摘要:

采用了基于密度泛函理论(DFT)的第一性原理平面波超软赝势方法，计算本征Al2O3，Co、Mo单掺杂以及Co-Mo共掺杂Al2O3的电子结构和光学性质. 计算结果表明： Mo单掺杂以及Co-Mo共掺杂Al2O3的结合能较低，比较容易合成. Co、Mo掺杂均属于n型掺杂，能够提升掺杂体系的载流子浓度，改善Al2O3的导电性. 掺杂体系的杂质能级主要由Co-3d态电子和Mo-4d态电子组成，这些杂质能级是改变掺杂Al2O3光学性质的内在原因. 掺杂后，吸收光谱发生红移现象，且光学性质变化主要集中要低能量范围. 本征Al2O3薄膜在200~800 nm范围内的透射率约为92%，Mo单掺杂和Co-Mo共掺杂Al2O3在600~780 nm波段内的透射率高达93%~98%，在200~280 nm的短波紫外光区域，Co单掺杂的透射率最高可达95%. 因此，三种掺杂Al2O3适用于制备各类光学透射膜.

Abstract:

The electronic structures and optical properties of intrinsic, Co, Mo doped and Co-Mo codoped Al2O3 compounds are calculated by using first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory. The results show that the binding energies of Mo single doping and Co-Mo co-doped Al2O3 are low and easy to synthesize. Both Co and Mo dopings belong to the n-type doping, which can enhance the carrier concentration of the doping system, and thus improving the conductivity of Al2O3. The impurity levels of the doped system are mainly composed of co-3d state electron and mo-4d state electron，which are the intrinsic factors that affect the optical properties of doped Al2O3. After doping, the absorption spectrum is redshifted and the optical properties change mainly in a low energy range. The transmittance of the Al2O3 film in the range of 200~800 nm is about 92%. The transmittances of the Al2O3 doped by Mo single and co-doped by Co-Mo are as high as 93~98% in the band of 600~780 nm. In the short-wave ultraviolet region of 200~280 nm, the transmittance of Co single doping can be as high as 95%. Therefore, three doped Al2O3 can be used to prepare various optical transmission films.