Orange-emitting zero-dimensional Te4+-Doped Cs2ScCl5·H2O perovskite microcrystals

Low-dimensional metal halide perovskites have gained the favor of many researchers for their potential applications in solid-state lighting due to their excellent optoelectronic properties. Herein, Te4+ doped Cs2ScCl5·H2O, a novel orange-emitting zero-dimensional scandium halide perovskite microcrystal was synthesized by hydrothermal method. Cs2ScCl5·H2O is isomorphic to Cs2InCl5·H2O with the space group Pnma. Under UV excitation, Cs2ScCl5·H2O:Te4+ exhibits a bright orange emission at 620 nm with a full width at half maximum (FWHM) of 170 nm, which is related to the formation of self-trapping excitons (STEs) in the zero-dimensional Te4+ doped Cs2ScCl5·H2O soft lattice. The fluorescence lifetime of Cs2ScCl5·H2O:Te4+ microcrystals are highly temperature-dependent with significant changes from microseconds (5.352 μs) at 110 K to nanoseconds (252 ns) at 298 K. The microcrystal-based white LED and thin film were initially explored for their potential application. These findings provide new insights into the excited state dynamics of Te4+ in Cs2ScCl5·H2O and demonstrate the potential application prospect for lead-free scandium halides doped by ns2 metal ions.