第一原理研究Sn(O_(1-x)N_x)_2材料的光电磁性质

First-principle study on optoelectronic and magnetic properties of Sn(O_(1-x)N_x)_2

基于第一原理的密度泛函理论,以量子化学从头计算软件为平台研究了Sn(O_(1-x)N_x)_2材料的光电磁性能,分析了体系的态密度、能带结构、磁性、介电虚部及折射率.计算结果表明,N替代O后,随着掺杂浓度的增加,体系的带隙先减小后增大,掺杂量为12.50%时带隙最窄.由于N 2p轨道电子的贡献,在0.55—1.05 eV范围内产生了浅受主能级,价带和导带处的能级均出现了劈裂及轨道的重叠现象,Sn—O键的键强大于N—O键的键强.从磁性来看,N原子决定了磁矩的大小.从介电虚部可知,掺杂后体系的光学吸收边增宽,主跃迁峰发生红移,反射率和介电谱相对应,各峰值与电子的跃迁吸收有关.

Optoelectronic and magnetic properties for Sn（O1-xNx）2 material were examined using quantum chemical ab initio calculation software WIEN2K based on the first principles of density functional theory.The density of states,the band structure,the magnetism, dielectric function and the refractive index are analyzed.The results show that the band gap frist narrowed and then increases with the increase of doping concentration of nitrogen substituting oxygen.the band gap of Sn（O1-xNx）2 becomes the narrowest when the concentration of nitrogen is 12.50%.As a result of the contribution of the electron of N 2p orbit,a low acceptor level appears in a range of 0.55—1.05 eV,and the level spliting and the orbit overlap appear in the valence band and conduction band.The Sn—O bond is stronger than the N—O bond.From the magnetism,the magnetic moment is determined by N atoms.We know that the optical absorption edge is widened from the imaginary part of dielectric function.The main transition peak is red shifted and the refractive index is corresponding to the dielectric function related to the transition of electrons.