第一性原理研究空位点缺陷对高压下LiF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 LiF under high pressure: A first principles investigation

作　　者：何旭[1] 何林[1] 唐明杰[1] 徐明[1] 

机构地区：[1]四川师范大学物理与电子工程学院,成都610068

出　　处：《物理学报》2011年第2期541-545,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10299040);四川师范大学科技基金资助的课题~~

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102GPa压力下LiF理想晶体、含Li-1空位和F+1空位点缺陷晶体时的电子结构和光学性质.结果表明:空位点缺陷的存在使得LiF能隙中出现了缺陷态;在可见光范围内,空位点缺陷的存在不会影响LiF的高压光吸收性(吸收系数仍为零);在紫外光波段,Li-1空位存在时在约99—114nm波段内出现了弱的吸收,F+1空位存在时在约99—262nm波段内出现了明显的吸收;Li-1,F+1两种空位分别存在时对LiF的反射谱和能量损失谱产生的影响都集中在紫外光区,与对光吸收产生的影响相似.By using the ultra-soft pseudo-potential approach of the plane wave based on the density-functional theory,the electronic structures and optical properties of LiF with Li-1 and F ＋1 vacancies are calculated. The results indicate that： （1） the presence of the vacancy causes defective states within the band gap of LiF; （2） the optical absorption of LiF in the visible-light region is not influenced by the vacancy point-defect （ absorption coefficients are still zero）; （3） in the ultra-violet region,the weak absorption induced by the Li-1 vacancy,appears within ～ 99—114 nm,and the relatively strong absorption induced by the F ＋1 vacancy exists in the range of 99—262 nm; （4） effects of the Li-1and F ＋1 vacancy on reflectivity and loss-function show mainly in the ultra-violet region,which is similar to those of optical absorption.

关 键 词：LIF 第一性原理 空位点缺陷 光学透明性 

分 类 号：O482.3[理学—固体物理]