Hyperfine interaction of electrons and holes with nuclei probed by optical orientation in MAPbI$_3$ perovskite crystals

TL;DR

This study investigates the hyperfine interaction between electron and hole spins and nuclear spins in MAPbI$_3$ perovskite crystals using optical orientation, revealing nuclear spin effects on spin dynamics at cryogenic temperatures.

Contribution

It provides the first detailed analysis of hyperfine interactions in MAPbI$_3$ perovskites through optical orientation measurements and evaluates nuclear spin fluctuation parameters.

Findings

Hyperfine interaction influences spin dynamics at cryogenic temperatures.

Nuclear spin polarization reaches 5 mT for electrons and -30 mT for holes.

Nuclear spin fluctuations within the localization volume are characterized.

Abstract

Optical orientation of electron and hole spins by circularly polarized light is investigated for MAPbI$_3$ single crystals. The Hanle and polarization recovery effects measured in transverse and longitudinal magnetic fields, respectively, evidence the hyperfine interaction with nuclear spins as the main factor determining the spin dynamics of charge carriers at cryogenic temperatures. The parameters of the nuclear spin fluctuations within the carrier localization volume are evaluated. Dynamic polarization of the nuclear spins is demonstrated by the Overhauser field reaching 5 mT for acting on the electrons and -30 mT for acting on the holes.