空位点缺陷对金刚石在高压下的电子结构和光学性质的影响  

Effects of the Vacancy Point-Defect on Electronic Structure and Optical Properties of Diamond under High Pressure

作　　者：何林[1] 尹君[1] 

机构地区：[1]四川师范大学物理与电子工程学院,四川成都610068

出　　处：《高压物理学报》2013年第6期802-806,共5页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(10299040);四川省教育厅科技基金(13ZA0152)

摘　　要：基于密度泛函理论框架下的平面波超软赝势方法,分别计算了255GPa压力下金刚石理想晶体以及含空位点缺陷晶体时的电子结构和光学性质。结果表明,在255GPa的冲击压力下,冲击诱导的空位点缺陷的存在使得在金刚石的能隙中出现了缺陷电子态;在可见光区390~570nm范围内产生了一定的光吸收,金刚石在该波段的光学透明性降低,但在可见光区的高波段金刚石却仍保持透明（其吸收系数仍为零）;空位点缺陷的存在对反射谱和能量损失谱的影响相似,谱主峰均向短波方向微移,且峰值强度都略有降低。By ultra-soft pseudo-potential approach of the plane wave based on the density-functional theory, the electronic structures and optical properties of diamond without and with vacancy point-defects were calculated at 255 GPa. The calculated results show that：at a shock pressure of 255 GPa,shock-induced vacancy point-defects in diamond crystal cause defective states within the band gap, and the optical absorption induced by the vacancy point-defects appears in the visible-light region of - 390- 570 nm, and there is the transparency loss of diamond in that region. However, in the visible-light region of -570-780 nm diamond remains transparent （it＇s optical- absorption coefficient is still zero）. Effects of shock-induced vacancy-defects on reflectivity and loss-function spectrums are similar： main-spectral peak move slightly toward short-wave region,and their intensity decreases to a small degree.

关 键 词：高压 空位点缺陷 金刚石 第一性原理 电子结构 光学性质 

分 类 号：O521.2[理学—高压高温物理] O483[理学—物理]