The Land\'e factors of electrons and holes in lead halide perovskites: universal dependence on the band gap

TL;DR

This study provides comprehensive experimental and theoretical analysis of electron and hole Landé factors in lead halide perovskites, revealing a universal dependence on the band gap energy across various material compositions.

Contribution

It introduces a universal semi-phenomenological model linking Landé factors to band gap energy, supported by extensive experimental data and first-principles calculations.

Findings

Landé factors vary systematically with band gap energy.

Universal dependence confirmed across different perovskite compositions.

Theoretical models accurately predict experimental Landé factors.

Abstract

The Land\'e or $g$-factors of charge carriers are decisive for the spin-dependent phenomena in solids and provide also information about the underlying electronic band structure. We present a comprehensive set of experimental data for values and anisotropies of the electron and hole Land\'e factors in hybrid organic-inorganic (MAPbI$_3$, MAPb(Br$_{0.5}$Cl$_{0.5}$)$_3$, MAPb(Br$_{0.05}$Cl$_{0.95}$)$_3$, FAPbBr$_3$, FA$_{0.9}$Cs$_{0.1}$PbI$_{2.8}$Br$_{0.2}$) and all-inorganic (CsPbBr$_3$) lead halide perovskites, determined by pump-probe Kerr rotation and spin-flip Raman scattering in magnetic fields up to 10~T at cryogenic temperatures. Further, we use first-principles DFT calculations in combination with tight-binding and $\mathbf k \cdot \mathbf p$ approaches to calculate microscopically the Land\'e factors. The results demonstrate their universal dependence on the band gap energy across the different perovskite material classes, which can be summarized in a universal semi-phenomenological expression, in good agreement with experiment.