Mn与非金属元素N,C,S共掺锐钛矿型TiO2电子性质和光学性质研究

摘要

金属与非金属共掺TiO2半导体以提高对可见光的利用率是近期研究的一个热点.本文通过基于密度泛函理论的平面波超软赝势方法,计算了Mn-N共掺杂、Mn-C共掺杂、Mn-S共掺杂TiO2晶体的能带、态密度、分态密度和光学性质.通过对比Mn-N共掺杂、Mn-C共掺杂、Mn-S共掺杂,这三种掺杂都在一定程度上改善了锐钛矿型二氧化钛对可见光的利用率,但Mn-C共掺杂相比于另外两种掺杂来说,对可见光的响应效果更好,电子从杂质能级跳跃到导带需要1.94 eV能量,该能量恰好对应可见光吸收光谱中的吸收峰.并且Mn-C共掺杂对可见光的的吸收率,反射率都远高于其它两种掺杂体系.%Recently,improving the visible light utilization by the metal and non-metallic impurities codoped TiO2 semiconductor is a research focus.In this paper,the band structures,density of states,partial density of states and optical properties of anatase TiO2 co-doped with Mn-N,Mn-C and Mn-S were studied by plane wave pseudopotential method based on the density functional theory.The results show that all the three co-dopings can improve the optical response of anatase TiO2,and the visible light response effect in Mn-C co-doped TiO2 is best.The electronic transition energy is about 1.94 eV (wavelength is 639nm) from impurity levels to conductor band,which exactly corresponds to the absorption peak in the visible light absorption spectrum.In addition,the absorptivity and the reflectivity of Mn-C co-doped TiO2 is better than those of the other two.