Room-temperature Magnetoresistance in Hybrid Halide Perovskites: Effect of Spin-Orbit Coupling

Abstract

Hybrid halide perovskites have emerged as promising materials for spintronics research due to their significant and tunable spin-orbit coupling (SOC). However, experimental findings that can discern the correlation between spintronic properties and SOC are rare. Here, we report the observation of room-temperature magnetoresistance (MR) and discuss the influence of chemical modification, hence SOC, in lead-based hybrid halide perovskites. Suppression of current under magnetic field (B) in perovskite thin films is explained in terms of field-modulated spin-mixing activity. We find that the MR increases upon replacement of ${\mathrm{I}}^{\ensuremath{-}}$ with ${\mathrm{Br}}^{\ensuremath{-}}$ and ${\mathrm{Cl}}^{\ensuremath{-}}$. The internal magnetic field parameter, i.e., HWHM of MR(B) reduces as we replace ${\mathrm{I}}^{\ensuremath{-}}$ by ${\mathrm{Br}}^{\ensuremath{-}}$ and ${\mathrm{Cl}}^{\ensuremath{-}}$ evidencing SOC is indeed weakened on substituting ${\mathrm{I}}^{\ensuremath{-}}$ with lighter halogen ions. Moreover, we analyze the effect of organic cation exchange by replacing ${\mathrm{MA}}^{+}$ with ${\mathrm{FA}}^{+}$ but no drastic change in MR response is observed. Our results successfully establish the crucial role played by SOC on MR for the development of spintronic devices, based on hybrid halide perovskites.