Exciton binding energy in a pyramidal quantum dot

Pramana: Journal of physics

M ARULMOZHI^2¹  A ANITHA^1,2² 

[1] Department of Physics, Jayaraj Annapackiam College for Women (Autonomous), Periyakulam, Theni District 625 601, India^2;Department of Physics, Mother Teresa Women’s University, Kodaikanal 624 101, India^1

关键词: Pyramid quantum dot;    dielectric screening function;    spatially dependent effective mass;    exciton;    GaAs;    non-parabolicity;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The effects of spatially dependent effective mass, non-parabolicity of the conduction band and dielectric screening function on exciton binding energy in a pyramid-shaped quantum dot of GaAs have been investigatedby variational method as a function of base width of the pyramid. We have assumed that the pyramid has a square base with area $a \times a$ and height of the pyramid $H = a/2$. The trial wave function of the exciton has been chosen according to the even mirror boundary condition, i.e. the wave function of the exciton at the boundary could be non-zero. The results show that (i) the non-parabolicity of the conduction band affects the light hole (lh) and heavy hole (hh) excitons to be more bound than that with parabolicity of the conduction band, (ii) the dielectric screening function (DSF) affects the lh and hh excitons to be more bound than that without the DSF and (iii) the spatially dependent effective mass (SDEM) affects the lh and hh excitons to be less bound than that without the SDEM. The combined effects of DSF and SDEM on exciton binding energy have also been calculated. The results are compared with those available in the literature.

【 授权许可】

CC BY