Optics of charged excitons in quantum wells: Free versus donor-bound complexes

TL;DR

This paper theoretically investigates how charged donors in quantum wells influence the localization and bound states of negatively charged excitons in magnetic fields, revealing new bound states with significant oscillator strengths.

Contribution

It introduces a detailed theoretical analysis of donor-bound charged excitons in quantum wells, identifying new bound states and their properties in magnetic fields.

Findings

Multiple bound states of charged excitons are supported by donors.

Discovery of new bound states with large oscillator strengths.

Dependence of bound states on donor position and magnetic field strength.

Abstract

We theoretically study localization of quasi-two-dimensional negatively charged excitons X^- on isolated charged donors in magnetic fields. We consider donors located in a barrier at various distances L from the heteroboundary as well as donors in the quantum well. We establish how many different singlet X_s^- and triplet X_t^- bound states a donor ion D^+ can support in magnetic fields B > 6 T. We find several new bound states, some of which have surprisingly large oscillator strengths.