Spin dependent charge transfer in MoSe2/hBN/Ni hybrid structures

TL;DR

This study demonstrates spin-dependent charge transfer in MoSe2/hBN/Ni structures, showing magnetization-controlled circular polarization of photoluminescence, with potential implications for spintronic devices.

Contribution

It provides experimental evidence of spin-dependent charge transfer in 2D heterostructures, revealing polarization control via ferromagnetic magnetization orientation.

Findings

Circular polarization reaches ~4% with Ni saturation

Polarization sign reverses with magnetization direction

Polarization persists up to 120 K

Abstract

We present magneto-photoluminescence measurements in a hybrid 2D semiconductor/ferromagnetic structure consisting of MoSe2/hBN/Ni. When the Nickel layer is magnetized, we observe circularly polarized photoluminescence of the trion peak in MoSe2 monolayer under linearly polarized excitation. This build-up of circular polarization can reach a measured value of about 4% when the magnetization of Ni is saturated perpendicularly to the sample plane, and changes its sign when the magnetization is reversed. The circular polarization decreases when the hBN barrier thickness increases. These results are interpreted in terms of a spin-dependent charge transfer between the MoSe2 monolayer and the Nickel film. The build-up of circular polarization is observed up to 120 K, mainly limited by the trion emission that vanishes with temperature.