Zr4+ and Bi3+ codoped Cs2Ag0.3Na0.7InCl6 double perovskite for single-composition white-light emitting phosphors and multimodal optical anti-counterfeiting

Abstract

Single-composition white-light emitter with excitation-dependent emissions is highly desired for phosphor-converted white-light emitting diodes (WLEDs) and optical anti-counterfeiting, in terms of the optical self-absorption and degeneration induced by the different components. However, the rational regulation of excitation-dependent multi-emissions in single perovskite materials is still a grand challenge. Herein, Bi3+ and Zr4+ codoped Cs2Ag0.3Na0.7InCl6 double perovskite microcrystals (DPMCs) were reported for single-composition white-light emitting phosphors and multimodal optical anti-counterfeiting. As a result, the photoluminescent quantum yield (PL QY) and color rendering index (CRI) were recorded up to 80.3% and 95.8, respectively. Specifically, under ultraviolet (UV) excitation at 365 nm, the Zr4+-doped DPMCs exhibited distinct emission profiles with single broad band centered at ∼570 nm for various Zr4+ doping concentrations, which could be attributed to the self-trapped exciton (STE) emission of the host. While the DPMCs show dual emission bands centered at ∼470 and ∼570 nm excited at 254 nm, which originates from the [ZrCl6]2- octahedral and STE, respectively, and their integral PL intensity ratio can be gradually adjusted by the content of Zr4+. The broad multicolor emissions with color kinetic features of the single-composition DPMCs offer exciting opportunities for constructing WLEDs and multimodal optical anti-counterfeiting.