nc-Si/SiO_2球形量子点的三阶极化率  

Third-order Nonlinear Susceptibility in a nc-Si/SiO_2 Spherical Quantum Dot

作　　者：刘明强[1] 郭震宁[1] 杨小儒[1] 

机构地区：[1]华侨大学信息科学与工程学院,福建泉州362021

出　　处：《华侨大学学报（自然科学版）》2009年第2期143-146,共4页Journal of Huaqiao University(Natural Science)

基　　金：福建省自然科学基金资助项目(E0410018);国务院侨办科研基金资助项目(06QZR02);泉州市科技计划重点项目(2008G7)

摘　　要：在有效质量近似下,采用无限深势阱,理论计算nc-Si/SiO2球形量子点导带中的电子束缚态,并利用紧束缚密度矩阵理论,推导出共振三阶极化率的表达式.通过数值模拟,分析讨论nc-Si/SiO2球形量子点的三阶极化率与量子点半径、入射光子的能量和弛豫相的关系.结果表明,在强受限中,三阶极化率与量子点半径、入射光子能量和弛豫相有着显著的关系.随着量子点半径的增大、入射光子能量的增大和弛豫相的减小,三阶极化率都有不同程度的增强.Under the effective mass approximation, the electron state is considered to be confined within a nc-Si/SiO2spherical quantum dot with infinite barrier, and by using the compact density matrix method, the analytic expression for the resonant third-order susceptibilities was derived. According to numerical simulation, the relation of the third-order susceptibilities with quantum dot dimension, incident photo energy and various relaxation rate was discussed. The result shows that the third-order susceptibilities strongly depends on quantum dot dimensions, incident photon energy and various relaxation rate. The third-order susceptibilities increases with an increase in quantum dot dimension and incident photo energy and a decrease in various relaxation rate.

关 键 词：量子点 无限深势阱 三阶极化率 nc-Si/SiO2 

分 类 号：O472.3[理学—半导体物理]