纳米Si薄膜光学性质和弹性常数的研究  

Study of Optical Properties and Elastic Constants on Nano-crystalline Silicon Thin Films

作　　者：梁伟华[1] 王秀丽[1] 赵亚军[1] 庞学霞[1] 王英龙[1] 

机构地区：[1]河北大学物理科学与技术学院,保定071002

出　　处：《材料导报》2012年第14期150-153,共4页Materials Reports

基　　金：国家重点基础研究发展计划(973计划)(2011CB612300);河北省教育厅资助项目(2009308)

摘　　要：采用基于密度泛函理论的第一性原理的方法,对厚度为0.54～3.30nm纳米Si薄膜的电子结构、光学性质及弹性常数进行了计算。结果表明,纳米Si薄膜是直接带隙半导体材料;随着纳米Si薄膜厚度的减小,带隙逐渐增大;薄膜的光学吸收边发生蓝移,吸收带出现宽化现象;弹性常数、杨氏模量和泊松比呈现尺寸效应。The electronic structural, optical properties and elastic constants of silicon films in large thickness range of 0.54-3.30nm were investigated by first-principles calculations based on density functional theory. The results show that the silicon films are direct-gap semiconductor materials; the band gap is widened with the decrease of thickness. Blue shift of the optical absorption edge is observed in the absorption spectra of silicon films with the decrease of thickness, accompanying with the widening of the absorption band. The elastic constants, Young＇s modulus and Poisson＇s ratio of silicon films are highly size dependent.

关 键 词：纳米Si薄膜 第一性原理 光学性质 弹性常数 

分 类 号：O469[理学—凝聚态物理] TB321[理学—电子物理学]