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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. 

Lanthanide (LnIII) ions were successfully chelated and sensitized with a tripodal ligand. The absolute LnIII-centered emission efficiencies were ~3% for both the europium(III) (EuIII) and terbium (TbIII) complexes and up to 54% for the cerium(III) (CeIII) complex. The differences in emission quantum yields for the early lanthanides (CeIII) and the mid lanthanides (EuIII and TbIII) were attributed to their d–f and f–f nature, respectively. Despite the low quantum yield of the EuIII complex, the combination of the residual ligand fluorescence and the red EuIII emission resulted in a bluish-white material with the Commission Internationale de l’Eclairage (CIE) coordinates (0.258, 0.242). Thus, metal complexes of the ligand could be used in the generation of single-component white-light-emitting materials. 

Scintillators, one of the essential components in medical imaging and security checking devices, rely heavily on rare‐earth‐containing inorganic materials. Here, a new type of organic‐inorganic hybrid scintillators containing earth abundant elements that can be prepared via low‐temperature processes is reported. With room temperature co‐crystallization of an aggregation‐induced emission (AIE) organic halide, 4‐(4‐(diphenylamino) phenyl)‐1‐(propyl)‐pyrindin‐1ium bromide (TPA‐PBr), and a metal halide, zinc bromide (ZnBr₂), a zero‐dimensional (0D) organic metal halide hybrid (TPA‐P)₂ZnBr₄with a yellowish‐green emission peaked at 550 nm has been developed. In this hybrid material, dramatically enhanced X‐ray scintillation of TPA‐P⁺is achieved via the sensitization by ZnBr₄²⁻. The absolute light yield (14,700 ± 800 Photons/MeV) of (TPA‐P)₂ZnBr₄is found to be higher than that of anthracene (≈13,500 Photons/MeV), a well‐known organic scintillator, while its X‐ray absorption is comparable to those of inorganic scintillators. With TPA‐P⁺as an emitting center, short photoluminescence and radioluminescence decay lifetimes of 3.56 and 9.96 ns have been achieved. Taking the advantages of high X‐ray absorption of metal halides and efficient radioluminescence with short decay lifetimes of organic cations, the material design paves a new pathway to address the issues of low X‐ray absorption of organic scintillators and long decay lifetimes of inorganic scintillators simultaneously.

 

The photophysical properties of square planar Pt(II) complexes are often strongly dependent on their self‐assembly modes and intermolecular Pt⋯Pt interactions. Controlling these interactions is important to achieve valuable properties for various applications, such as light‐emitting diodes and environmental sensing devices. Herein, a series of highly luminescent ionic Pt(II) complexes with tunable emission colors are reported, by controlling the molecular structures and interactions in solid state. Four ionic Pt(II) complexes, with a general formula [Pt(C^{^}N)(N^{^}N)]⁺X⁻(C^{^}N = 2‐phenylpyridine or 2‐(2,4‐difluorophenyl)pyridine; N^{^}N = 2,2′‐bipyridine; X⁻= chloride (Cl⁻) or tetraphenylborate (BPh₄⁻), are designed, synthesized, and characterized. Due to the presence of intermolecular Pt⋯Pt interactions, strong metal–metal‐to‐ligand charge transfer (MMLCT) emissions are recorded in all four complexes with color changing from green to deep red in solid state. A high photoluminescence quantum efficiency (PLQE) of 81% is achieved for one of the complexes containing large BPh₄⁻anions, due to the site isolation effects. Detailed structural and photophysical characterizations reveal a clear correlation between the stacking of these Pt(II) complexes and their photophysical properties, which can be well regulated by the molecular structures and counter‐anions.

 

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.

 

Zero‐dimensional (0D) organic metal halide hybrids (OMHHs) have recently emerged as a new class of light emitting materials with exceptional color tunability. While near‐unity photoluminescence quantum efficiencies (PLQEs) are routinely obtained for a large number of 0D OMHHs, it remains challenging to apply them as emitter for electrically driven light emitting diodes (LEDs), largely due to the low conductivity of wide bandgap organic cations. Here, the development of a new OMHH, triphenyl(9‐phenyl‐9H‐carbazol‐3‐yl) phosphonium antimony bromide (TPPcarzSbBr₄), as emitter for efficient LEDs, which consists of semiconducting organic cations (TPPcarz⁺) and light emitting antimony bromide anions (Sb₂Br₈²⁻), is reported. By replacing one of the phenyl groups in a well‐known tetraphenylphosphonium cation (TPP⁺) with an electroactive phenylcarbazole group, a semiconducting TPPcarz⁺cation is developed for the preparation of red emitting 0D TPPcarzSbBr₄single crystals with a high PLQE of 93.8%. With solution processed TPPcarzSbBr₄thin films (PLQE of 86.1%) as light emitting layer, red LEDs are fabricated to exhibit an external quantum efficiency (EQE) of 5.12%, a peak luminance of 5957 cd m⁻², and a current efficiency of 14.2 cd A⁻¹, which are the best values reported to date for electroluminescence devices based on 0D OMHHs.