Surface-enhanced spin current to charge current conversion efficiency in CH3NH3PbBr3-based devices

Dali Sun; Chuang Zhang; Marzieh Kavand; Jingying Wang; Hans Malissa; Haoliang Liu; Henna Popli; Jaspal Singh; Shai R Vardeny; Wei Zhang; Christoph Boehme; Z Valy Vardeny

doi:10.1063/1.5125230

Surface-enhanced spin current to charge current conversion efficiency in CH₃NH₃PbBr₃-based devices

J Chem Phys. 2019 Nov 7;151(17):174709. doi: 10.1063/1.5125230.

Authors

Affiliations

¹ Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA.
² Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
³ Department of Physics, Oakland University, Rochester, Michigan 48309, USA.

PMID: 31703503
DOI: 10.1063/1.5125230

Abstract

Hybrid organic-inorganic perovskites have shown great promise for spintronic applications due to their large spin-orbit coupling induced by the Pb and halogen atoms. Particularly, the large observed surface-induced Rashba splitting in CH₃NH₃PbBr₃ indicates efficient spin-current-to-charge-current (StC) conversion, which, however, has not been demonstrated yet. In this work, the StC conversion efficiency in ferromagnet/CH₃NH₃PbBr₃-based devices is studied using the pulsed spin-pumping technique measured by the inverse spin Hall effect. We found that the StC conversion efficiency is anomalous in that it increases at small perovskite layer thickness. This indicates the existence of a surface-dominated StC mechanism such as the inverse Rashba-Edelstein effect. By inserting a thin LiF layer between the ferromagnet and the perovskite film, the StC conversion efficiency is greatly suppressed, validating the existence of a Rashba surface in the CH₃NH₃PbBr₃ film.