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

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 MA(0.3)FA(0.7)PbI(3) and MA(0.3)FA(0.7)Pb(0.5)Sn(0.5)I(3) 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 & eacute; 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.

Automated summary

This study systematically investigates the coherent spin precession, dephasing and relaxation processes of electrons and holes in two hybrid organic-inorganic metal halide perovskites. The results show that these materials exhibit robust spin precession and the spin dephasing and relaxation processes may be influenced by defect levels. Temperature-dependent measurements provide insights into the spin relaxation channels. The extracted electron Land & eacute; g-factors have the largest values reported in inorganic or hybrid perovskites. Both the electron and hole g-factors show significant shifts with temperature, which is proposed to be due to thermal lattice vibration effects on the band structure. These findings lay the groundwork for further design and application of lead- and tin-based perovskites in spintronic devices.