摘要
在连续介电模型和有效质量近似下,考虑电子有效质量随位置的变化,利用变分法从理论上研究了半导体有限高势垒球形量子点中杂质态的结合能.数值计算了AlxGa1-xAs/GaAs球形量子点杂质态基态结合能随量子点尺寸和垒材料Al组分的变化关系,讨论了有效质量随位置变化对基态结合能的影响,并与不考虑有效质量随位置变化做了比较.结果表明:当量子点半径较小时,电子有效质量随位置的变化增加了杂质态基态结合能,随量子点半径增大,杂质态基态结合能的增加幅度变小;量子点半径较大时,电子有效质量随位置变化降低了杂质态基态结合能.随着Al组分增大,杂质态基态结合能单调递增.
Under a continuous dielectric model within the effective mass approximation, by considering the position-dependent electron effective mass,the binding energy of impurity states in a finite-potential spherical quantum dot is studied by using the variational procedure. Numerical method is used to perform the binding energy of ground state of impurity state in a AlxGa^-. As/ GaAs spherical quantum dot as a function of dot size and AI composition of barrier material. The influence of the position-dependent effective mass on the binding energy is discussed and compared with the case that the effective mass as a constant. The results show that when the quantum dot radius is small, the position-dependent electron effective mass increases the impurity binding energy of ground state,with the dot radius increasing,the increase amplitude of impurity state can become smaller ~ when the dot radius is large, the position-dependent electron effective mass reduces the impurity binding energy of ground state. As the A1 component increases, the ground state binding energy of impurity state increases monotonically.
出处
《内蒙古大学学报（自然科学版）》
CAS
北大核心
2017年第1期55-60,共6页
Journal of Inner Mongolia University：Natural Science Edition
基金
国家自然科学基金资助项目(No.1364028)
内蒙古自然科学基金重大项目(No.2013ZD02)资助
内蒙古"草原英才"工程资助项目
关键词
量子点
杂质态
有效质量
结合能
quantum dot
impurity state
effective mass
binding energy
