Modulated energy transfer in Eu3+-doped Cs3TbCl6 nanocrystals for single-component white-light emission and anti-counterfeiting

White light-emitting diodes (WLEDs) have garnered significant attention due to their key applications in lighting and display technologies, especially in the development of single-component white-light-emitting materials. Herein, we synthesized Cs 3 TbCl 6 nanocrystals (NCs) with tunable white light emission by introducing Eu 3+ ions. The single-component white-light emission comprises blue, green, and red components, originating from self-trapped exciton, Tb 3+ , and Eu 3+ emissions, respectively. Through precisely controlled Eu 3+ doping, we achieve a high energy transfer efficiency of 48.3% from Tb 3+ to Eu 3+ , which is attributed to the enhanced spatial overlap between electrons and holes as revealed by spectroscopic analysis and density functional theory calculations. The fabricated WLED devices based on Cs 3 TbCl 6 :Eu 3+ NCs exhibit excellent performance with a half-life exceeding 330 h, Commission International de l’Eclairage (CIE) coordinates of (0.316, 0.330), and a high color rendering index (CRI) of 89.4. Furthermore, the excitation-dependent emissions enable effective anti-counterfeiting and information encryption functionalities. This study presents a robust ionic doping strategy for modulating energy transfer in single-component white light-emitting nanomaterials, offering promising potential for applications in lighting, display, and information security technologies.