Exciton–phonon interactions and exciton pure dephasing in lens-shaped quantum dots

We have investigated exciton–phonon coupling and a zero-phonon exciton absorption line shape for lens-shaped quantum dots (QDs). Such dots occur in quasi-monolayer semiconductor heterostructures due to the interfacial roughness making quasi-2D excitons localize in lens-shaped quantum dot-like islands. The lateral size dependence calculated of low-temperature Huang–Rhys factors indicates the enhancement of exciton–phonon coupling with decreasing the lateral size of the quasi-2D exciton localization area. The low-temperature zero-phonon line exhibits an essentially non-Lorentzian asymmetric shape with the asymmetry increasing with the decrease of temperature and the lateral size of the quasi-2D exciton localization area.