Electronic Structure of Quantum-Dot Quantum-WellSemiconductor Heterostructures

摘要

We analyse semiconductor quantum-dot quantum-well (QDQW)heterostructures. Using the nonsymmetrized 8-band effective-mass model,electron, hole and exciton states are described in CdS/HgS/CdS/H2O andCdTe/HgTe/CdTe/H2O QDQWs. The exciton energy spectrum has beenobtained taking into account both Coulomb and spin-exchange interactions.The optical absorption spectra of the QDQWs calculated using ournonadiabatic theory are compared to those obtained within the adiabaticapproximation. It is seen that, within the nonadiabatic theory, phononassistedcontributions to the absorption spectrum are substantially enhancedas compared to those given by the adiabatic approximation.