functional luminescent materials due to diversified photoluminescence (PL) performance and ultrahigh emission efficiency with unique applications in solid-state light emitting diodes, X-ray scintillation, remote thermography, etc. [7][8][9][10][11] Especially, the 0D organic-inorganic hybrid perovskites deliver highly adjustable structural architectures and PL properties derived from the synergistic effect of versatile organic species and anionic blocks. [12][13][14] In these 0D hybrid perovskites, the spatially discrete metal halide units are wrapped by bulk organic components with perfect core-shell structures from molecular level, which mean that the semiconducting halide species periodically embed in the insulated organic matrix as light emitting centers. Benefiting from the strong spatial and quantum confinement effect from organic walls, the photoinduced carriers are highly localized in the discrete metal halide species, which leads to firmly confined bound excitons with large exciton binding energy and high photoluminescence quantum yield (PLQY) at room temperature. [15][16][17] At the same time, the strong electron-quantum coupling transiently localizes the excitons along with large excited-state structural deformation, which produces self-trapped excitons (STEs) with lower excited state energy. Therefore, 0D perovskites incline to display intrinsic lower-energy broadband light emissions with large Stokesshifts, which are different from the narrow emission bands of 3D APbX 3 PQDs. [18][19][20][21][22] As a result, lower-energy green, yellow, and red light emissions are easily realized in 0D halide perovskites, but higher-energy blue light emission remains extremely challenging, especially in pure-blue spectral region (460-480 nm). [23][24][25][26] Simultaneously considering the biological toxicity of Pb 2+ ion and lower PLQY of blue emitting perovskite, it is greatly significant and stringent to design lead-free 0D perovskites comprising environment-friendly metals as highly efficient blue emitters to achieve balanced development of three primary-color in high-definition display and lighting devices.Another critical bottleneck that restricts the practical applications of perovskites is the poor stability toward various chemical and physical factors including water, humid air, polar solvents, light, etc., due to the ionic nature of material itself. [27] As a result, the PL emission is easily quenched by these external stimuli along with the structural decomposition or phase transitions, especially perovskites without additional protection Despite remarkable luminescent performance of 0D lead halide perovskites, achieving highly efficient blue light emission is extremely challenging and crucial for this domain. Considering the high toxicity of Pb 2+ ion, it is significant to explore water-stable lead-free 0D halides as highly efficient and stable blue emitting materials. To address these issues, a family of 0D hybrid zinc halides of AZnBr 4 (A = EP, BP, and TMPDA) based on discrete [ZnBr 4 ] 2− tetrahedrons...
