Lead-free metal halides with stable and tunable emission have shown great promise for broad application prospects in the visible light range. However, it remains a fundamental challenge to realize tunable near-infrared (NIR) luminescence in these metal halide materials. Herein, a cation regulation strategy in zero-dimension organic metal halides AZnCl:Sb (A = Rb, Cs) to achieve tunable NIR luminescence is reported. The prepared AZnCl:Sb (A = Rb, Cs) halides exhibited efficient broadband NIR emission, which originates from self-trapped excitons of the [SbCl] polyhedron. Based on the regulation of cation, the [SbCl] tetrahedral distortion capacity changes, exciton–phonon coupling is enhanced, leading to a red shift of the emission wavelength. The results provide inspiration for the regulation of the self-trapped excitons luminescence of halides and demonstrate potential as a non-visible light source for night vision.

中文翻译：

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A2ZnCl4 (A= Rb, Cs) 金属卤化物中的锑掺杂可实现可调谐近红外发射

具有稳定和可调发射特性的无铅金属卤化物在可见光范围内显示出广阔的应用前景。然而，在这些金属卤化物材料中实现可调谐近红外（NIR）发光仍然是一个根本挑战。本文报道了零维有机金属卤化物 AZnCl:Sb (A = Rb, Cs) 中的阳离子调节策略，以实现可调谐近红外发光。制备的 AZnCl:Sb (A = Rb, Cs) 卤化物表现出高效的宽带近红外发射，其源自 [SbCl] 多面体的自陷激子。基于阳离子的调控，[SbCl]四面体畸变能力发生变化，激子-声子耦合增强，导致发射波长红移。这些结果为卤化物自俘获激子发光的调控提供了灵感，并展示了作为夜视不可见光源的潜力。