在有效质量近似下采用变分法计算了Cd1-x Mnx Te/CdTe抛物量子阱 内不同Mn组分下激子的结合能, 给出了结合能在不同Mn组分下随阱宽、垒宽、外加电场的变化情况。 结果表明:激子结合能是阱宽的一个非单调函数,随阱宽的变化呈现先增加后减小的趋势,而且随着Mn组分增大, 激子结合能达到最大值的阱宽相应变小, 这与材料的带隙改变有关;激子结合能随垒宽逐渐增大然后趋于稳定值,这与波函数向垒中的渗透有关； 在一定范围内电场对激子结合能的影响很小,而且Mn组分越大对激子结合能影响越小,但电场强度较大时 会破坏激子效应。计算结果可以为基于半导体抛物形量子阱发光器件设计制作提供一些理论依据。

Exciton binding energies in Cd1-x Mnx Te/CdTe parabolic quantum well (PQW) with different Mn contents were calculated through variational method in the effective mass approximation. The variations of exciton binding energy as a function of well width, barrier width and electric field were calculated with different Mn compostions. The results show that the exciton binding energy is a non-monotonic function of well width. It increases first until reaching a maximum, and then decreases as the well width increases farther. In addition, with the increase of Mn content the well width should decrease to reach the maximum value of the exciton binding energy due to the change of material band gap. The exciton binding energy increases first until reaching a stable value with the increase of barrier width, which is related to the barrier penetration of wave function. The external electric field has little effect on binding energy, and the effect decreases with the increase of Mn content, but when the electric field is large enough, it will destroy the excitonic effect. The results are meaningful in design of optoelectronic device based on PQW.