Behavior of optoelectronic properties of exciton-phonon in a multilayered cylindrical quantum well wires-dot with two finite confinement potentials structures

The optoelectronic properties of an exciton confined in multilayered cylindrical quantum well wires and quantum dots are investigated taking into account the finite confinement potentials of the first and second materials. We explore two types of confinement potentials, referred to as type A and type B. Type A considers that the potential energy of the first layer is lower than the second layer on the other hand in type B the potential energy of the first layer is higher than the second layer. The couplage of the confined longitudinal optical (LO) phonons with the exciton is included in this study through Frohlich and the Lee-Low Pines unitary transformation. In the presence and the absence of the LO-phonon modes, the binding energy and the interband emission energy (photoluminescence) of exciton are calculated using the effective mass approximation in parallel with a variational technique. The effect of core size, layers thickness and barrier materials potentials as well as switching between two structures types on excitonic properties are also investigated. It was discovered that, the contribution of the LO-phonon modes and the augmentation of the barrier material potential tends to increase the value of the exciton energies, and that the confinement potentials types have no influence on the latter quantities when the thickness of the first layer is greater than 6 nm. Also, for a fixed core radius, when the second layer radius is high (low), the first (second) potential influence of the layers on the energies is more evident. However, in the (A)-type and (B)-type of the confinement potential, the photoluminescence energy increases and decreases, respectively, with the decrease of the first layer radius, when R12 <= 6 nm. The findings of the binding energy and photoluminescence might be used to adjust the optoelectronic device's properties based on the low dimensional nanostructures.