Non-circular semiconductor nanorings of type I and II: Emission kinetics in the exciton Aharonov-Bohm effect

TL;DR

This paper investigates exciton emission and Aharonov-Bohm oscillations in non-circular semiconductor nanorings, revealing how shape deviations and non-radiative decay influence optical properties and magnetic field responses.

Contribution

It introduces a detailed analysis of exciton kinetics and optical spectra in non-circular type I and II nanorings, highlighting shape effects and non-radiative decay impacts.

Findings

Non-circular shape enhances Aharonov-Bohm oscillation observability.

Non-radiative decay causes photoluminescence quenching with magnetic field.

Ground state remains optically active in slightly deformed nanorings.

Abstract

Transition energies and oscillator strengths of excitons in dependence on magnetic field are investigated in type I and II semiconductor nanorings. A slight deviation from circular (concentric) shape of the type II nanoring gives a better observability of the Aharonov-Bohm oscillations since the ground state is always optically active. Kinetic equations for the exciton occupation are solved with acoustic phonon scattering as the major relaxation process, and absorption and luminescence spectra are calculated showing deviations from equilibrium. The presence of a non-radiative exciton decay leads to a quenching of the integrated photoluminescence with magnetic field.