Exciton-polaron in a CdSe quantum dot under an applied magnetic field

Abstract

We investigate theoretically the interaction between excitons and longitudinal optical (LO) phonons in a cylindrical disk-like semiconductor quantum dot under a magnetic field. The created bare exciton is further dressing with LO phonons, which results in arising a composite quasi-particle being the coherent mixture of the electron-hole pair and phonons that can be called exciton–polaron in analogy to the Fröhlich electron–phonon. We calculate the quantum dot radius dependences of the exciton–polaron energy. We show that the exciton energy spectrum changes significantly when taking into account the interaction with LO phonons. The effect of the temperature on the integrated photoluminescence intensity is also investigated. We observe that at relatively high temperature the magnetic field and the quantum dot height have noticeable effects on the photoluminescence intensity.