Photoluminescence from localized states in disordered indium nitride

TL;DR

This study investigates the photoluminescence properties of disordered indium nitride under high magnetic fields, revealing highly localized excitonic states with implications for understanding disorder effects in semiconductors.

Contribution

It provides new insights into the localization of excitonic states in disordered InN through high-field photoluminescence measurements and diamagnetic shift analysis.

Findings

Localized excitonic wave functions are only 2-3nm in extent.

Photoluminescence peaks at 0.82 and 0.98 eV indicate disorder-related states.

Temperature dependence supports the presence of trapped carriers.

Abstract

Photoluminescence spectra from disordered InN were studied in very high magnetic fields. The samples had Gaussian spectra with low temperature emission peaks at 0.82 and 0.98eV respectively. The average spatial extent of the excitonic wave functions, inferred from the diamagnetic shift, is only 2-3nm. This shows that the recombination is from an ensemble of highly localized states within a landscape of a smooth (classical) disorder potential of strength of the order of 10meV. The anomalies in the temperature dependence of the photoluminescence peak and linewidth give further support to the picture of trapped photoexcited carriers.