Single-component zero-dimensional (BPY)2ZrCl6:Sb3+ hybrid perovskite exhibiting excitation-dependent multi-color fluorescence and afterglow for advanced hierarchical anti-counterfeiting

Abstract

Single-component materials capable of exhibiting both excitation-dependent fluorescence and time-resolved afterglow are highly desirable for advanced photonic applications, yet remain scarce. Herein, we report a novel zero-dimensional (0D) organic–inorganic hybrid perovskite (OIHP), (BPY)₂ZrCl₆:Sb³⁺([BPY]⁺ = N-butyl-pyridinium cation), which exhibits excitation-dependent fluorescence and green afterglow properties. This dual emission originates from distinct luminescent centers: self-trapped excitons (STEs) and d–d transitions within the [ZrCl₆]²⁻ octahedra, and the organic [BPY]⁺ cations. The incorporation of Sb³⁺ enables efficient energy transfer from the host to the [SbCl₆]³⁻ dopant, leading to broadly tunable white-light emission from green to orange-red and a notable reduction in afterglow lifetime. Density functional theory calculations revealed the origin of the afterglow, and the band narrowing and exciton localization effects caused by Sb³⁺ doping. Leveraging this tunable emission and time-resolved afterglow, we demonstrate high-quality white light-emitting diodes (WLEDs) and a dynamic anti-counterfeiting system using ASCII-based time-gated decoding. This work provides insights into energy-transfer engineering in 0D OIHP and establishes a material platform that integrates efficient lighting with advanced information encryption.