Dielectric confinement of excitons in type-I and type-II semiconductor nanorods

TL;DR

This paper theoretically investigates how the dielectric environment influences exciton properties in semiconductor nanorods, revealing environment-dependent emission shifts, recombination rates, and charge distributions, especially in type-II structures.

Contribution

It provides a detailed theoretical analysis of dielectric effects on excitons in nanorods, highlighting how insulating environments alter optical and electronic properties.

Findings

Insulating environments enhance exciton recombination rates.

Emission peaks blueshift by tens of meV due to dielectric confinement.

Dielectric effects can modify charge spatial distribution in type-II nanorods.

Abstract

We theoretically study the effect of the dielectric environment on the exciton ground state of CdSe and CdTe/CdSe/CdTe nanorods. We show that insulating environments enhance the exciton recombination rate and blueshift the emission peak by tens of meV. These effects are particularly pronounced for type-II nanorods. In these structures, the dielectric confinement may even modify the spatial distribution of electron and hole charges. A critical electric field is required to separate electrons from holes, whose value increases with the insulating strength of the surroundings.