Tunable Multicolor Emission and High Thermal Stability in Single-Matrix Luminescent Crystals Based on Calcium Perovskites for Advanced Solid-State Lighting Applications

The development of environmentally friendly full-inorganic luminescent materials with tunable emission properties and exceptional thermal stability is of paramount importance for applications in optoelectronic devices, solid-state lighting, and anti-counterfeiting technologies. In this study, a novel luminescent crystal based on calcium perovskites Cs 2 CaCl 4 ·2H 2 O (CCCH) are explored using a hydrothermal method. Simultaneous co-doping of CCCH with Sn 2+ and Mn 2+ yields the s-p transition-induced cyan light from Sn 2+ and d-d transition-induced yellow light from Mn 2+ . It demonstrates effective energy transfer from self-trapped exciton (STE) of matrix CCCH and s-p transition of Sn 2+ to Mn 2+ , synergizing composite white lights with tunable colors. Furthermore, the incorporation of Sn 2+ into CCCH introduces a red shift from blue to cyan emission with a remarkable enhancement in luminescent intensity by a factor of 12 times. The crystal orbital Hamiltonian populations (─COHP) calculations revealed the crucial role of Mn 2+ in lattice stability, as evidenced by the decomposition temperature exceeding 305 °C for CCCH:Sn 2+ ,Mn 2+ whereas 210 °C for undoped CCCH matrix. This research provides a comprehensive investigation of the luminescent properties of CCCH:Sn 2+ ,Mn 2+ crystal, holding significant promise for practical technological advancements in lighting and anti-counterfeiting technologies.