Ultrastable 0D Organic Zinc Halides with Highly Efficient Blue Light Emissions

Abstract 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 Pb²⁺ 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 AZnBr₄ (A = EP, BP, and TMPDA) based on discrete [ZnBr₄]²⁻ tetrahedrons is herein reported as desirable blue light emitters. The wide band gaps enable these 0D halides to display highly efficient blue light emissions (452–485 nm) with highest photoluminescence quantum yield (PLQY) of 35.47%. More importantly, all these 0D halides present extraordinary chemical stabilities in humid air and water for one month, and are also capable of withstanding extreme pH conditions in the range of 0–14, likely the widest observed pH range for perovskites. Notably, the ultrahigh chemical stabilities of 0D zinc halides are nearly unmatchable among all known literature perovskite materials to the best of the authors’ knowledge. Combined superiorities of unusual blue light emission, promising PLQY, ultrahigh stability, and non‐toxicity highlight the potential optoelectronic applications in wide chemical environments for these 0D zinc halides.