使用有效质量模型, 从理论上对GaAs/Al0.35Ga0.65As不对称耦合量子点在不同耦合强度下束缚态和反束缚态的能级分裂情况进行了详细分析, 重点探讨了电子和空穴的耦合隧穿对量子点体系能级特征及激子发光强度的影响。研究发现: 不对称耦合量子点在外电场作用下价带束缚态和反束缚态能级出现反交现象, 反交处的能级分裂值和临界电场随量子点间距的增加而减小;对应的激子发光强度也经历了从亮(暗)到暗(亮)激子的转变。

We theoretically analyzed the bonding and anti-bonding energy states in the GaAs/Al0.35Ga0.65As asymmetric coupled quantum dots under a series of electric fields. The carrier tunneling effect strongly influences the exciton energy and oscillator strength.We find that energy splitting of anti-crossing occurs under an critical electric field for hole bounding and anti-bonding states, and both the energy gap and the critical field decrease with increasing the barrier distance. Meanwhile, the exciton luminescence intensity changes from bright(dark) to dark(bright) under external fields.