Tunable green luminescence in Eu-doped SrZrS₃ perovskite with air stability

Chalcogenide perovskite has attracted significant attention as a potential optoelectronic material due to its excellent light absorption, suitable direct band gap, and effective carrier transportation. While the luminescence properties of Sr-based chalcogenides have been explored recently, challenges such as low luminescence efficiency and limited performance persist. In this work, rare earth element Eu, which possesses distinctive luminescent properties, was selected to tune the luminescent properties of chalcogenide perovskites. The synthesized Eu-doped SrZrS₃ powders are demonstrated to exhibit enhanced green light emission at 550 nm under 350 nm excitation, which is attributed to the 4f⁶5d¹-4f⁷5d⁰ transition of Eu²⁺. Moreover, an investigation into the temperature-dependent luminescent measurements reveals that the PL intensity of the optimized 8 at% Eu-doped specimen at 380 K remains at 50 % of that at 280 K. In addition to the well-performed thermal stability and photostability, this material exhibits excellent air stability, even when stored in air for over a year. Moreover, the direct bandgap characteristics are confirmed through experiments and calculations. And the application of this material in the luminescent anticounterfeiting field was preliminarily explored. These findings offer an approach to tune the luminescence performance of chalcogenide perovskites and promote their potential applications in the field of luminescence.