SiO_2中包埋纳米晶Si光电性质的计算  

Calculation of Optoelectronic Properties of Si Nanocrystals Embedded in SiO_2

作　　者：柴跃生[1,2] 罗春云[2] 张敏刚[2] 伍静[2] 

机构地区：[1]上海大学材料科学与工程学院,上海200072 [2]太原科技大学材料科学与工程学院,太原030024

出　　处：《人工晶体学报》2009年第5期1216-1220,共5页Journal of Synthetic Crystals

基　　金：山西省自然科学基金(No.20041073)

摘　　要：采用第一性原理平面波赝势方法计算了SiO2基质包埋不同尺寸纳米晶粒Si3和Si5的电子结构及光学性质。结果表明,随着包埋纳米晶粒尺寸的减小,包埋Si3结构的带隙比包埋Si5结构宽,但包埋Si5结构对可见光区的吸收优于包埋Si3结构。Si3结构的第一个吸收峰在约3.9eV处,Si5结构的第一个吸收峰在约4.6eV处。计算表明,Si纳米颗粒中Si原子数与包埋基质的分子数之比为45.46%是一种较好的结构参数,对可见光区吸收效果好。The electronic structure and optical properties of Si3 and Si5 nanocrystals with different sizes embedded in SiO2 have been investigated by first-principles pseudopotential plane-wave method. The results show the bandgap of Si3 embeded structure is wider than Si5 embeded structure,with the sizes of silicon nanocrystals embedded in SiO2 decreasing,while the absorption efficiency of Si5 embeded structure for visible light is better than Si3 embeded structure. The first absorption peak of Si3 embeded structure is at about 3.9 eV and Si5 embeded structure is at about 4.6 eV. Calculation shows 45.46%,the proportion of the Si atoms of silicon nanocrystals to the molecular number of substrate,is a better structure parameters,which is good for the absorption efficiency of visible light at this ratio.

关 键 词：第一性原理 密度泛函理论 价键畸变 态密度 

分 类 号：O471.5[理学—半导体物理]