Investigation of the confined states and oscillator strength of conical quantum dots with wetting layer embedded in nanowire

摘要

The quantum dots embedded in nanowires are of great interest for their applications in nanolasers and quantum emitters. In this regard, the electronic confined states and optical properties of an InAs conical quantum dot located on an InAs wetting layer and embedded in an infinite GaAs nanowire are investigated theoretically. This is accomplished by numerically solving the Schrodinger equation using the effective mass approximation. The results show the existence of an energy continuum for each cannel of angular momentum whose lower limit raises by the angular momentum. This causes discrete bound states of higher angular momentum to lie in the continuum of the lower ones. On the other hand, although the confined energy levels decrease smoothly by increasing the nanowire radius, their decline by dot radius and height represents some step-like features. This effect could be explained based on the relative concentration of the electron probability density in the dot and wetting layer. Finally the oscillation strength for intersubband transition between confined energy states of the system have been investigated.