Abstract
Understanding the feasibility to couple semiconducting and magnetic properties in metal halide perovskites through interface design opens new opportunities for creating the next generation spin-related optoelectronics. In this work, a fundamentally new phenomenon of optically induced magnetization achieved by coupling photoexcited orbital magnetic dipoles with magnetic spins at perovskite/ferromagnetic interface is discovered. The depth-sensitive polarized neutron reflectometry combined with in situ photoexcitation setup, constitutes key evidence of this novel effect. It is demonstrated that a circularly polarized photoexcitation induces a stable magnetization signal within the depth up to 7.5 nm into the surface of high-quality perovskite (MAPbBr3) film underneath a ferromagnetic cobalt layer at room temperature. In contrast, a linearly polarized light does not induce any detectable magnetization in the MAPbBr3. The observation reveals that photoexcited orbital magnetic dipoles at the surface of perovskite are coupled with the spins of the ferromagnetic atoms at the interface, leading to an optically induced magnetization within the perovskite’s surface. The finding demonstrates that perovskite semiconductor can be bridged with magnetism through optically controllable method at room temperature in this heterojunction design. This provides the new concept of utilizing spin and orbital degrees of freedom in new-generation spin-related optoelectronic devices.
| Original language | English |
|---|---|
| Article number | 2004488 |
| Journal | Advanced Science |
| Volume | 8 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jun 9 2021 |
Funding
This research was supported by the Asian Office of Aerospace Research and Development (AOARD) (FA2386‐17‐1‐4060) and the National Science Foundation (NSF‐1911659). This research used resources at the Spallation Neutron Source, a Department of Energy (DOE) Office of Science User Facility operated by the Oak Ridge National Laboratory. Optical characterization was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. The authors thank the Center for Materials Processing, a Center of Excellence at the University of Tennessee, Knoxville, funded by the Tennessee Higher Education Commission, for financial support (M.W.). This research was supported by the Asian Office of Aerospace Research and Development (AOARD) (FA2386-17-1-4060) and the National Science Foundation (NSF-1911659). This research used resources at the Spallation Neutron Source, a Department of Energy (DOE) Office of Science User Facility operated by the Oak Ridge National Laboratory. Optical characterization was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. The authors thank the Center for Materials Processing, a Center of Excellence at the University of Tennessee, Knoxville, funded by the Tennessee Higher Education Commission, for financial support (M.W.).
Keywords
- heterojunction
- hybrid perovskite
- photoinduced magnetization
- polarized neutron reflectometry
- spintronics