MnSb-based spin LED with side-wall emission

Abstract

Combination of the spin-dependent optical transition and the spin current would lead us to the opportunity of developing photo- and light-emitting diodes that respectively senses and emits circularly polarized light. Here, we describe preparation of spin LED consisting of an epitaxial MnSb spin injection layer and GaAs-AlGaAs double hetero-structures, and show characteristics of EL from a side wall emission. Taking advantage of remnant state of ferromagnet, circular polarization emission has been realized without application of an external field. Demonstration of electrical switching of circular polarization has been carried out with alternative switching between two spin-LEDs having antiparallel magnetization configuration. While the technique used in the present demonstration was a crude one, it certainly show the feasibility of building a compact and robust light source whose circular polarization is controlled electrically. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.