Room-Temperature Magnetic Field Effect on Excitonic Photoluminescence in Perovskite Nanocrystals.

Zhang, Kun; Zhao, Jian; Hu, Qingsong; Yang, Sijie; Zhu, Xixiang; Zhang, Yaqi; Huang, Ruiqin; Ma, Yongfu et al. · Adv Mater · 2021

basic_science · Level V

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Abstract

Magnetic-field-enhanced spin-polarized electronic/optical properties in semiconductors are crucial for fabricating various spintronic devices. However, this spin polarization is governed by weak spin exchange interactions and easily randomized by thermal fluctuations; therefore, it is only produced at cryogenic temperatures, which severely limits the applications. Herein, a room-temperature intrinsic magnetic field effect (MFE) on excitonic photoluminescence is achieved in CsPbX<sub>3</sub> :Mn (X = Cl, Br) perovskite nanocrystals. Through moderate Mn doping, the MFE is enhanced by exciton-Mn interactions, and through partial Br substitution, the MFE is stabilized at room temperature by exciton orbital ordering. The orbital ordering significantly enhances the g-factor difference between electrons and holes, which is evidenced by a parallel orbit-orbit interaction among excitons generated by circular polarized laser excitation. This study provides a clear avenue for engineering spintronic materials based on orbital interactions in perovskites.