Spin Coherence and Spin Relaxation in Hybrid Organic-Inorganic Lead and Mixed Lead-Tin Perovskites

TL;DR

This study investigates spin coherence, dephasing, and relaxation in hybrid organic-inorganic lead and tin perovskites using time-resolved Faraday rotation, revealing long-lived spin precession and temperature-dependent g-factors relevant for spintronics.

Contribution

It provides the first systematic analysis of spin dynamics in these perovskites, highlighting their potential for spintronic device applications.

Findings

Robust Larmor spin precession persists for hundreds of picoseconds.

Electron g-factors are among the largest reported for perovskites.

Temperature significantly affects g-factors and spin relaxation channels.

Abstract

Metal halide perovskites make up a promising class of materials for semiconductor spintronics. Here we report a systematic investigation of coherent spin precession, spin dephasing and spin relaxation of electrons and holes in two hybrid organic-inorganic perovskites MA0.3FA0.7PbI3 and MA0.3FA0.7Pb0.5Sn0.5I3 using time-resolved Faraday rotation spectroscopy. With applied in-plane magnetic fields, we observe robust Larmor spin precession of electrons and holes that persists for hundreds of picoseconds. The spin dephasing and relaxation processes are likely to be sensitive to the defect levels. Temperature-dependent measurements give further insights into the spin relaxation channels. The extracted electron Land\'e g-factors (3.75 and 4.36) are the biggest among the reported values in inorganic or hybrid perovskites. Both the electron and hole g-factors shift dramatically with temperature, which we propose to originate from thermal lattice vibration effects on the band structure. These results lay the foundation for further design and use of lead- and tin-based perovskites for spintronic applications.