AlGaAs插入层对InAs/AlGaAs/GaAs量子点的尺寸分布影响

The Effect of AlGaAs Cladding Layer on Size Distribution of InAs/AlGaAs/GaAs Quantum Dots

采用MBE系统,在GaAs(001)表面用S-K模式分别在原子级平坦的GaAs和AlGaAs/GaAs表面沉积3 ML的InAs量子点,利用STM研究了AlGaAs插入层对InAs/GaAs量子点尺寸分布的影响。研究发现,AlGaAs插入层会使InAs/GaAs量子点平均尺寸变小,而尺寸分布变得分散;采用不同的InAs沉积速率生长量子点,发现随着InAs沉积速率的加快,量子点平均尺寸变小,密度增大,尺寸分布更为集中。

3 monolayer InAs quantum dots were deposited on flat GaAs（ 001） surface and AlGaAs/GaAs surface respectively in a Stranski-Krastanow model by MBE. The effect of AlGaAs cladding layer on the size distribution of InAs/GaAs quantum dots was studied by using STM. Results show that AlGaAs cladding layer will make the average size of InAs/AlGaAs/GaAs quantum dots decrease and the size distribution more scattered. By adopting InAs quantum dots with different deposition rates,it can be found that with the increase of deposition rate,the average size of quantum dot decreases,the density increases and the size distribution is more concentrated.