Coherent spin dynamics of electrons and holes in CsPbBr3 perovskite crystals

Vasilii V Belykh,Dmitry N Dirin,Mikhail M Glazov,Maksym V Kovalenko,Dmitri R Yakovlev,Philipp S Grigoryev,Janina Rautert,Mujtaba Hussain,Manfred Bayer

doi:10.1038/s41467-019-08625-z

Abstract

The lead halide perovskites demonstrate huge potential for optoelectronic applications, high energy radiation detectors, light emitting devices and solar energy harvesting. Those materials exhibit strong spin-orbit coupling enabling efficient optical orientation of carrier spins in perovskite-based devices with performance controlled by a magnetic field. Here we show that elaborated time-resolved spectroscopy involving strong magnetic fields can be successfully used for perovskites. We perform a comprehensive study of high-quality lead halide perovskite CsPbBr3 crystals by measuring the exciton and charge carrier g-factors, spin relaxation times and hyperfine interaction of carrier and nuclear spins by means of coherent spin dynamics. Owing to their ‘inverted’ band structure, perovskites represent appealing model systems for semiconductor spintronics exploiting the valence band hole spins, while in conventional semiconductors the conduction band electrons are considered for spin functionality.

Highlights

Semiconductor spintronics is an intense research field covering the whole variety of spin-dependent phenomena and numerous experimental techniques, which allow one to study the spin structure and spin dynamics in different materials and their nanostructures
We focus on the coherent spin dynamics in external magnetic fields at cryogenic temperatures studied by optical techniques based on the pump–probe time-resolved Kerr rotation
In a longitudinal magnetic field of BF = 10 T the reflectivity spectra measured in the two opposite circular polarizations show an exciton Zeeman splitting of ΔEZ = 1.32 meV (Fig. 1b), which corresponds to the exciton g-factor gX = ΔEZ/(μBBF) = 2.35, where μB is the Bohr magneton

Summary

Introduction

Semiconductor spintronics is an intense research field covering the whole variety of spin-dependent phenomena and numerous experimental techniques, which allow one to study the spin structure and spin dynamics in different materials and their nanostructures. Despite the great recent interest to various perovskite materials[1,2,3,4], including two-dimensional perovskites and colloidal nanocrystals, spin studies are at the very beginning here, while substantial bulk and structure inversion asymmetry[5,6,7] make perovskites promising for spintronics[8,9] It has been demonstrated, that experimental approaches like optical orientation[10], spin polarization induced by magnetic field[11,12], pump–probe Faraday rotation[13,14], and single dot spectroscopy in magnetic field[15,16,17] are working well for perovskites and their nanostructures.

Methods

Results

Conclusion