Carrier localization in defected areas of (Cd, Mn)Te quantum well investigated via Optically Detected Magnetic Resonance employed in the microscale

TL;DR

This study investigates how defects in (Cd, Mn)Te quantum wells affect carrier localization, impacting local conductivity and excitonic properties, using spatially resolved ODMR techniques to reveal localized carriers near dislocations.

Contribution

It introduces a spatially resolved ODMR method to analyze carrier localization effects in defected quantum well regions, revealing localized carriers near dislocations.

Findings

Defected areas show reduced local conductivity.

Knight shift remains unchanged in defected regions.

Carrier localization occurs near dislocations.

Abstract

In this work, we study the impact of carrier localization on three quantities sensitive to carrier gas density at the micrometer scale: charged exciton (X+) oscillator strength, local free carrier conductivity, and the Knight shift. The last two are observed in a micrometer-scale, spatially resolved optically detected magnetic resonance experiment (ODMR). On the surface of MBE-grown (Cd,Mn)Te quantum well we identify defected areas in the vicinity of dislocations. We find that these areas show a much lower conductivity signal while maintaining the same Knight shift values as the pristine areas of the quantum well. We attribute this behavior to carrier localization in the defected regions.