导带弯曲对球形量子点光学性质的影响及压力效应  

Effects of Band Bending and Hydrostatic Pressure on Optical Properties of a Hydrogenic Impurity in a Spherical Quantum Dot

作　　者：裴立群[1] 闫祖威[1,2] 

机构地区：[1]内蒙古大学物理科学与技术学院,呼和浩特010021 [2]内蒙古农业大学理学院,呼和浩特010018

出　　处：《内蒙古大学学报（自然科学版）》2014年第3期265-272,共8页Journal of Inner Mongolia University：Natural Science Edition

基　　金：国家自然科学基金资助项目(1364028);内蒙古自然科学基金重大项目(2013ZD02)资助

摘　　要：在有效质量近似下,采用三角势近似异质结界面处导带弯曲,并计及流体静压力效应,利用变分原理研究了有限高势垒GaN/AlxCa1-xN球形量子点杂质态一阶线性和三阶非线性光吸收系数随着电子面密度及流体静压力的变化关系.数值计算结果指出,随电子面密度的增加,吸收系数峰值的位置向短波方向移动(即蓝移),且一阶线性吸收峰随之增高,三阶非线性吸收峰随之降低;随压力的增加,吸收系数峰值的位置先向长波方向移动(红移),然后向短波方向移动(蓝移),且一阶线性吸收峰随之降低,三阶非线性吸收峰随之升高.结果表明,压力效应是明显的,导带弯曲效应是不可忽略的.In the effective mass approximation, the optical properties for the ls 2p0 transitions are calculated for a hydrogenic impurity in the center of a spherical quantum dot by using a triangu lar potential to approximate the band bending of the interface potential, under hydrostatic pressure. The linear and the third-order nonlinear optical absorption coefficients are investigated for different electron areal densities and hydrostatic pressures. The results indicate that the peak positions of the absorption coefficients show a blue-shift with increase of the electron areal density,and both of the linear optical absorption coefficient and the total optical absorption coefficient rise while the third- order nonlinear optical absorption coefficient reduces. With the increase of hydrostatic pressure,the peak positions of the absorption coefficients have a red shift at first and then a blue-shift occur,the numerical value of the optical absorption coefficients also changes obviously. In brief,the band ben ding and hydrostatic pressure have a significant effect on the optical characteristics of this nano structure.

关 键 词：球形量子点 光吸收系数 导带弯曲 压力 

分 类 号：O471.3[理学—半导体物理]