Highly polarized injection luminescence in forward-biased ferromagnetic-semiconductor junctions at low spin polarization of current

TL;DR

This paper explores how electron tunneling from a nonmagnetic semiconductor into a ferromagnet can produce highly polarized luminescence at low current spin polarization, useful for spin-based light sources.

Contribution

It demonstrates a method to generate highly polarized light via electron tunneling in FM-S heterostructures at low spin polarization levels.

Findings

Efficient spin extraction near FM-S interface at low current polarization.

Polarized radiation depends on bias voltage applied to the junction.

Potential application in spin-polarized light sources.

Abstract

We consider electron tunneling from a nonmagnetic $n$-type semiconductor ($n$-S) into a ferromagnet (FM) through a very thin forward-biased Schottky barrier resulting in efficient extraction of electron spin from a thin $n$-S layer near FM-S interface at low spin polarization of the current. We show that this effect can be used for an efficient polarization radiation source in a heterostructure where the accumulated spin polarized electrons are injected from $n$-S and recombine with holes in a quantum well. The radiation polarization depends on a bias voltage applied to the FM-S junction.