Population Inversion Induced by Resonant States in Semiconductors

TL;DR

This paper predicts a new mechanism for carrier population inversion in semiconductors caused by resonant states under electric fields, supported by calculations relevant to recent THz lasing experiments.

Contribution

It introduces a novel population inversion mechanism based on resonant state scattering, expanding understanding of semiconductor lasing phenomena.

Findings

Theoretical prediction of population inversion via resonant states.

Calculations for strained p-Ge support the mechanism.

Potential explanation for recent THz lasing observations.

Abstract

We present a theoretical prediction of a new mechanism for carrier population inversion in semiconductors under an applied electric field. The mechanism is originated from a coherent capture-emission type inelastic scattering of resonant states. We support our theory with concrete calculations for shallow acceptor resonant states in strained p-Ge where a lasing in THz frequency region has been recently observed.