中文摘要：

采用第一性原理，以WIEN2K软件为平台对Sn1-xNxO2超晶胞体系的态密度（DOS）、能带结构、介电函数和吸收系数进行模拟计算，从理论上指出光学特性与电子结构之间的内在联系。分析结果表明：掺入杂质后体系带隙减小了0．59eV，费米能级向低能方向移动进入价带，并且由半导体变为半金属材料，N的掺入有助于P型SnO2的实现；掺杂前后体系为直接跃迁半导体，其介电函数谱和吸收谱与带隙相对应均发生了红移，并且光学吸收边变宽，增大了光学响应，Sn1-xNxO2材料可广泛应用于红外发光器件。

英文摘要：

Adopting first principles and using WIEN2K software for the platform to present the states （DOS） ,band structure, die- lectric function and the absorption coefficient of Sn1-xNxO2 ,we point out the intrinsic relationship between optical properties and elec- tronic structure theoretically. The results show that the band gap of the impurity-doped system reduces by 0.59 eV,fermi levels shift to lower energy and go into the valence band, and the semiconductor materials change into half metal materials, and confirms the fact that N-doped SnO2 helps the formation of p-type SnO2 ;the systems are direct transition semiconductor, the imaginary part of the dielectric function and absorption coefficient make a red shift corresponding to the band gaps, and the optical absorption boundary gets wider, and increases the optical response,so Sn1-xNxO2 materials will be widely applied in infrared light-emitting device.