Spin Dynamics of Electrons and Holes Interacting with Nuclei in MAPbI3 Perovskite Single Crystals

Methylammonium lead triiodine (MAPbI$_3$) is a material representative of the\nhybrid organic-inorganic lead halide perovskites which attract currently great\nattention due to their photovoltaic efficiency and bright optoelectronic\nproperties. Here, the coherent spin dynamics of charge carriers and spin\ndependent phenomena induced by the carrier interaction with nuclear spins are\nstudied in MAPbI$_3$ single crystals, using time-resolved Kerr rotation at\ncryogenic temperatures in magnetic fields up to 3 T. Spin dephasing times up to\na few nanoseconds and a longitudinal spin relaxation time of 37 ns are\nmeasured. The Larmor spin precession of both resident electrons and holes is\nidentified in the Kerr rotation signals. The Land\\'e factors ($g$-factors) in\nthe orthorhombic crystal phase show a strong anisotropy, ranging for the holes\nfrom $-0.28$ to $-0.71$ and for the electrons from $+2.46$ to $+2.98$, while\nthe $g$-factor dispersion of about 1% is rather small. An exciton $g$-factor of\n$+2.3$ is measured by magneto-reflectivity. A dynamic nuclear polarization by\nmeans of spin polarized electrons and holes is achieved in tilted magnetic\nfields giving access to the carrier-nuclei exchange interaction and the nuclei\nspin relaxation time exceeding 16 minutes.\n