C掺杂β-Si_3N_4的电子结构和光学性质  

Electronic Structure and Optical Properties of β-Si_3N_4 Doped with C

作　　者：潘洪哲[1,2] 

机构地区：[1]临沂师范学院物理系,山东临沂276005 [2]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室,四川绵阳621900

出　　处：《临沂师范学院学报》2008年第6期30-33,共4页Journal of Linyi Teachers' College

摘　　要：运用密度泛函平面波赝势方法(PWP)和广义梯度近似(GGA),对替代式C掺杂β-Si3N4的超晶胞电子结构进行了模拟计算,分析了β-Si3N4:C的电子结构和光学性质.对C掺杂前后电子结构的异同以及价键的一些性质进行了对比分析发现,由于C的掺杂,价带宽度展宽,导带宽度和禁带宽度均变窄;态密度出现了几个新的峰,平均峰值有所减小.通过对比分析光吸收系数发现,相对于β-Si3N4的光吸收系数,β-Si3N4:C的吸收系数有所降低,并且向长波方向移动,100nm处的吸收峰向长波方向移动约11.8nm.The electronic structures and optical properties of β-Si3N4：C super-cell have been calculated by means of plane wave pseudo-potential method （PWP） within generalized gradient approximation （GGA）. After doping with C, it has been found that valence-band width is widened while the conduction-band width and band gap become narrow; several peaks appear and average energy level decreases by about 5 electron/eV. The absorption coefficient of β-Si3N4：C significantly reduces in comparison to that of β-Si3N4 and optical absorption peak at 100 nm has a shift of about 11.8 nm to the long-wave direction.

关 键 词：平面波赝势方法 密度泛函理论 b相氮化硅 C掺杂 

分 类 号：O731[理学—晶体学] O734