Tunable Spectral Emission from 0D Rb₃ZnBr₅ Crystals for Single‐Component Multi‐Color LED Applications

Abstract The development of efficient, stable, and cost‐effective luminescent materials is crucial for advancing lighting and display technologies. In this study, a series of tunable luminescent materials based on the novel 0D all‐inorganic perovskite (AIP) crystal Rb₃ZnBr₅ (RZB) is obtained. The emission of Sn 2 ⁺ doped RZB spans the entire visible light range and extends into the near‐infrared (NIR) region, achieving a photoluminescence quantum yield (PLQY) of 75%. The distinct lifetimes combined with theoretical calculations, indicate that the broadband dual‐peak emissions at 496 and 636 nm originate from the singlet and triplet states of Sn 2 ⁺, respectively, which is rarely observed in Sn 2 ⁺‐doped perovskite crystals. The phosphor RZB:Sn 2 ⁺ demonstrates the high thermal stability, along with excellent moisture and air stability. Co‐doping RZB with Sn 2 ⁺ and Mn 2 ⁺ broadens the excitation spectrum and allows precise control over the excitation wavelength, facilitating dynamic transitions from warm white to yellow and green light. This feature is particularly beneficial for multicolor LEDs and multi‐level anti‐counterfeiting applications.