Highly efficient room temperature spin injection in a metal-insulator-semiconductor light emitting diode

TL;DR

This paper reports highly efficient spin injection at room temperature in a semiconductor LED using a novel tunnel barrier, achieving significant spin polarization at both low and room temperatures.

Contribution

The study introduces a double-step oxide deposition technique for creating a pinhole-free AlOx tunnel barrier, enabling efficient spin injection at room temperature.

Findings

Spin polarization of at least 24% at 80K

Spin polarization of 12% at room temperature

Use of a double-step oxide deposition for improved tunnel barrier quality

Abstract

We demonstrate highly efficient spin injection at low and room temperature in an AlGaAs/GaAs semiconductor heterostructure from a CoFe/AlOx tunnel spin injector. We use a double-step oxide deposition for the fabrication of a pinhole-free AlOx tunnel barrier. The measurements of the circular polarization of the electroluminescence in the Oblique Hanle Effect geometry reveal injected spin polarizations of at least 24% at 80K and 12% at room temperature.