4H-SiC材料中刃型位错的仿真模拟研究

摘要

A model of threading edge dislocation (TED) of 4H-SiC scaled 6 × 6 × 1 is presented in Castep Simulator.By adopting this software, the relative properties of TED are obtained and analyzed based on the first - principle.It is found that the bandgap become narrow and a new little peak appeared in the density of states at the bottom of conduction band compared to the ideal crystal lattice.It is due to the existence of dangling bonds to introduce a dislocation energy level in forbidden band nearby the bottom of conduction band.%根据4H-SiC刃型位错的特点,在Castep软件中建立了6×6×1的刃型位错模型.基于第一性原理,利用Castep程序对刃型位错的相关性质进行了计算,并与完整晶格的模拟结果进行了对比.结果表明在引入刃型位错之后,4H-SiC材料的带隙变窄,在靠近导带底部态密度出现了一个新的峰值,这主要是由位错芯处的悬挂键在禁带中引入了一个缺陷能级所致.