第一性原理计算N掺杂对InNbO_4电子结构的影响

N doping influences on electronic structure of InNbO_4 from first-principles calculations

宽带隙(3.83 e V)半导体光催化材料InNbO_4在紫外光作用下具有分解水和降解有机物的性能.最近实验发现了N掺杂InNbO_4具有可见光下分解水制氢的活性.为了从理论上解释这一实验现象,本文采用基于密度泛函理论的第一性原理计算了N掺杂对InNbO_4的能带结构、态密度和光学性质的影响.分析能带结构可得,N掺杂后在InNbO_4的价带(O 2p)上方形成N 2p局域能级,导致电子跃迁所需的能量减小.吸收光谱表明,N掺杂后InNbO_4的光吸收边出现了红移,实现了可见光吸收.

Indium niobate（ InNbO_4）,as a wide band gap（ 3. 83 e V） photocatalyst,could split the water and decompose the organic compounds under UV light irradiation. Recently,nitrogen doping InNbO_4 was prepared and exhibited the photocatalytic activity of hydrogen generation upon visible light irradiation. In order to explain this phenomenon,the geometry structure,density of states and optical properties of N doped InNbO_4 were investigated by first- principles method based on the density function theory. The calculated band structures indicated that some N 2p states were located above the valance band,which led to the reduction of the electron transition energy. The absorption spectra showed that the N- doped InNbO_4 shifted its absorption edge from UV region to visible light region.