有限拋物量子井施子雜質的光游離化之計算

Abstract

本論文在研究有限拋物量子井中施子雜質的光游離化截面積大小。首先，我們計算由III-V族半導體異質結構GaAs/A1xGaix-As所形成的拋物線型量子井的基態能量與波函數。其次是以類氫原子的波函數乘上拋物線量子井基態的波函數，當作施子雜質在此拋物型量子井裡的基態波函數數，然後以變分法求得其態的束縛能。最後，將所求得的解代入光游離化面積的公式，求出不同入射光能量與光游離化截面積大小的關係。 從結果中，我們得到了量子井的寬度及深度對電子束能以及光游離化截面積大小的影響。

In this thesis, we discussed the size of the photoinonization cross section of donor impurity in a finite parabolic quantum well. First, the groundstate energies and wave functions of finite parabolic quantum wells of GaAs surrounded by A1xGa1x As are calculated. Next, the binding energies of ground-state are evaluated for donor impurity in the wells with a variation method, using the wave functions that are the product of the hydrogenic wave functions and the wave functions of finite parabolic quantum wells. Finally, the photon energy dependence of the photoionization cross sections is calculated by using the formula of photoionization cross section of bulk case. The result we obtained shows the binding energies and the photoionization cross-sections are affected by the width and the depth of the quantum wells.