Multicolor luminescence of In ³⁺ /Mn ²⁺ alloying in K ₃ SbCl ₆ synthesized via mechanochemistry

Here, the spectroscopic characterization of In³⁺/Mn²⁺ alloying in K₃SbCl₆ fluorescent material synthesized via mechanochemistry is investigated using thermal-related steady-state and time-resolved photoluminescence (PL) spectroscopy. Under 360 nm ultraviolet light excitation, K₃SbCl₆ exhibits a broad yellow emission peaking at 592 nm. Subsequently, by alloying In³⁺/Mn²⁺with a specific molar ratio, tunable multicolor emission is achieved in the spectral region from blue-green to red. This represents the first, to the best of our knowledge, successful alloying of In³⁺ in antimony (Sb)-based chlorides synthesized via mechanochemistry. Furthermore, temperature-dependent PL reveals a pronounced thermochromic response for K₃SbCl₆, with emission shifting from green through yellow to orange within 160-250 K. Finally, yellow, green, and red light-emitting diodes fabricated from pure and In³⁺/Mn²⁺-alloyed K₃SbCl₆ confirm its practical potential in solid-state lighting.