对称GaAs/Al_(0.3)Ga_(0.7)As双量子阱中激子的束缚能

Binding energies of excitons in symmetrical GaAs/Al_(0.3)Ga_(0.7) As double quantum wells

在有效质量近似下采用简单的尝试波函数变分地计算了对称GaAs/Al0·3Ga0·7As双量子阱中激子体系束缚能,研究了体系束缚能随阱宽和垒宽的变化情况.发现双量子阱中激子体系束缚能随阱宽变化同单量子阱情况类似,但束缚能的峰值出现在阱宽为10左右,峰值位置小于单阱的情况;束缚能随垒宽的增加有一极小值,这与波函数向垒中的渗透有关.

The binding energies of excitons in symmetrical GaAs/Al0.3Ga0.7As double quantum wells are calculated variationally by using a simple wave function within the effective-mass approximation. The variation of the binding energies as functions of the well and barrier width is studied. It is found that, the changing tendency of the binding energies with the well width is similar to that of the single quantum well. However, we found that the maximum value of the binding energy occurs at well size of about 10A°. The well size is smaller than that in single quantum wells. The binding energies have a minimum during the increase of the barrier width, which is related to the penetration into the barrier of the wave function.