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Manganese-based organic–inorganic metal halide composites have been considered as promising candidates for lead-free emitters. However, in spite of their excellent luminescence properties in green and red regions, blue emission—a critical component for white light generation—from pristine manganese-based composites is currently missing. In this work, we successfully achieve blue luminescence center in manganese-based composites through selecting specific organic component methylbenzylamine (MBA). Our approach is fundamentally different from green and red emission in manganese-based composites, which result from manganese-halide frameworks. The coexistence of different luminescence centers in our manganese-based composites is confirmed by photoluminescence (PL) and photoluminescence excitation (PLE) results. As a result of different photoluminescence excitation responses of different emission centers, the resulting emission color can be tuned with selecting different excitation wavelengths. Specifically, a white light emission can be obtained with Commission Internationale de l'éclairage coordinates of (0.33, 0.35) upon the 330 nm excitation. We further demonstrate the promise of our manganese-based composites in the anti-counterfeiting technology and multicolor lighting. Our results provide a novel strategy for full-spectral emission in manganese-based organic–inorganic metal halide composites and lay a solid foundation for a range of new applications. [ABSTRACT FROM AUTHOR]

Incorporating chiral organic compounds into metal halide frames is a common and useful method to introduce chirality in metal halide composites. The structures of resulting racemic and chiral composites are usually considered to be nearly identical owing to similar chemical bonding. In this work, by incorporating chiral MBABr (bromide methylbenzylamine) into an inorganic frame, a significant crystallization difference between the resulting racemic and chiral metal halide composites is observed, as confirmed by both structural and spectroscopic measurements. In addition, the structural transformation in the chiral composites can also be induced by moisture, ascribed to the asymmetric hydrogen bonding in chiral materials. These results provide new insights for the future synthesis of chiral materials and open up new possibilities to advance the materials functionalities. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Optically Induced Static Magnetization: Optically Induced Static Magnetization in Metal Halide Perovskite for Spin-Related Optoelectronics (Adv. Sci. 11/2021) In operando polarized neutron reflectometry combined with in situ photoexcitation, constitutes key evidence of this novel effect. In article 2004488, Miaosheng Wang, Valeria Lauter, Bin Hu and co-workers discovered a fundamentally new phenomenon of optically induced magnetization achieved by coupling photoexcited orbital magnetic dipoles with magnetic spins at perovskite/ferromagnetic interface. [Extracted from the article]