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Light emitting diodes (LEDs) have wide applications from fullcolor displays to solid‐state lighting. Numerous types of luminescent materials have been explored for LEDs, ranging from inorganic semiconductors to metal complexes and quantum dots. Despite the rapid pace of development, LEDs have not achieved their full potentials in terms of performance and cost efficiency. Identifying new eco‐friendly materials for LEDs is of great interest. Recently, metal halide perovskites and perovskite‐related hybrid materials have emerged as new generation luminescent materials with unique optoelectronic properties. Here, some of our recent development of LEDs based on metal halide perovskites and perovskite‐related materials will be discussed. 

An AIE organic zinc chloride complex scintillator, in which the metal halide serves as X-ray sensitizer for the organic component, is discovered to exhibit a light yield of 13 423 Photon per MeV and a radioluminescence decay lifetime of 5.24 ns. 

Organic metal halide hybrids with low-dimensional structures at the molecular level have received great attention recently for their exceptional structural tunability and unique photophysical properties. Here we report for the first time the synthesis and characterization of a one-dimensional (1D) organic metal halide hybrid, which contains metal halide nanoribbons with a width of three octahedral units. It is found that this material with a chemical formula C 8 H 28 N 5 Pb 3 Cl 11 shows a dual emission with a photoluminescence quantum efficiency (PLQE) of around 25%. Photophysical studies and density functional theory (DFT) calculations suggest the coexisting of delocalized free excitons and localized self-trapped excitons in metal halide nanoribbons leading to the dual emission. 

Abstract 0D organic metal halide hybrids (OMHHs) have recently emerged as a new generation of scintillation materials, due to their high luminescence quantum efficiency, sensitivity, stability, and cost‐effectiveness. While numerous 0D OMHH scintillators have been developed to date, most of them are based on solution grown single crystals that require time‐consuming synthesis and are limited in size. Here, high‐performance X‐ray scintillators based on facile solution processed 0D OMHH amorphous films are reported for the first time. By reacting triphenyl(9‐phenyl‐9H‐carbazol‐3‐yl) phosphonium bromide (TPPcarzBr) with manganese bromide (MnBr₂), 0D (TPPcarz)₂MnBr₄ amorphous films can be prepared via solution processing with mild thermal annealing, which exhibits green photoluminescence with an emission maximum ≈517 nm and a photoluminescence quantum efficiency of ≈87%. The X‐ray scintillation of 0D (TPPcarz)₂MnBr₄ amorphous films is characterized to exhibit a light yield of 44600 photon MeV⁻¹and an outstanding linearity with a low limit of detection of 32.42 nGy_airs⁻¹over a wide range of X‐ray dose rates. The versatile processability of 0D (TPPcarz)₂MnBr₄ is illustrated with remarkable recyclability, high cost‐effectiveness, and scalability for large‐scale production. By taking advantage of the amorphous nature of newly designed OMHHs, the approach opens up new opportunities for developing high‐performance, solution‐processable scintillators. 

Abstract Low dimensional (LD) organic metal halide hybrids (OMHHs) have recently emerged as new generation functional materials with exceptional structural and property tunability. Despite the remarkable advances in the development of LD OMHHs, optical properties have been the major functionality extensively investigated for most of LD OMHHs developed to date, while other properties, such as magnetic and electronic properties, remain significantly under‐explored. Here, we report for the first time the characterization of the magnetic and electronic properties of a 1D OMHH, organic‐copper (II) chloride hybrid (C₈H₂₂N₂)Cu₂Cl₆. Owing to the antiferromagnetic coupling between Cu atoms through chloride bridges in 1D [Cu₂Cl₆²⁻]_∞chains, (C₈H₂₂N₂)Cu₂Cl₆is found to exhibit antiferromagnetic ordering with a Néel temperature of 24 K. The two‐terminal (2T) electrical measurement on a (C₈H₂₂N₂)Cu₂Cl₆single crystal reveals its insulating nature. This work shows the potential of LD OMHHs as a highly tunable quantum material platform for spintronics. 

Metal-halide perovskites, in particular their nanocrystal forms, have emerged as a new generation of light-emitting materials with exceptional optical properties, including narrow emissions covering the whole visible region with high photoluminescence quantum efficiencies of up to near-unity. Remarkable progress has been achieved over the last few years in the areas of materials development and device integration. A variety of synthetic approaches have been established to precisely control the compositions and microstructures of metal-halide perovskite nanocrystals (NCs) with tunable bandgaps and emission colors. The use of metal-halide perovskite NCs as active materials for optoelectronic devices has been extensively explored. Here, we provide a brief overview of recent advances in the development and application of metal-halide perovskite NCs. From color tuning via ion exchange and manipulation of quantum size effects, to stability enhancement via surface passivation, new chemistry for materials development is discussed. In addition, processes in optoelectronic devices based on metal-halide perovskite NCs, in particular, light-emitting diodes and radiation detectors, will be introduced. Opportunities for future research in metal-halide perovskite NCs are provided as well. 

Abstract Scintillation based X-ray detection has received great attention for its application in a wide range of areas from security to healthcare. Here, we report highly efficient X-ray scintillators with state-of-the-art performance based on an organic metal halide, ethylenebis-triphenylphosphonium manganese (II) bromide ((C₃₈H₃₄P₂)MnBr₄), which can be prepared using a facile solution growth method at room temperature to form inch sized single crystals. This zero-dimensional organic metal halide hybrid exhibits green emission peaked at 517 nm with a photoluminescence quantum efficiency of ~ 95%. Its X-ray scintillation properties are characterized with an excellent linear response to X-ray dose rate, a high light yield of ~ 80,000 photon MeV⁻¹, and a low detection limit of 72.8 nGy s⁻¹. X-ray imaging tests show that scintillators based on (C₃₈H₃₄P₂)MnBr₄powders provide an excellent visualization tool for X-ray radiography, and high resolution flexible scintillators can be fabricated by blending (C₃₈H₃₄P₂)MnBr₄powders with polydimethylsiloxane.