Highly emissive Sb³⁺-doped Rb₂InCl₅?H₂O perovskites: cost-effective synthesis, luminescence, and its application

Zero-dimensional (0D) lead-free halide perovskites are emerging as promising light-emitters, which can be applied as light conversion materials for illumination and display. Herein, we prepared a series of Sb3+:Rb2InCl5 & BULL;H2O perovskites by a simple and efficient coprecipitation method. The Rb2InCl5 & BULL;H2O perovskite gives no emission due to the parity-forbidden transition. When Sb3+ is doped into Rb2InCl5 & BULL;H2O, radiative transition occurs. Under 365 nm excitation, the Sb3+:Rb2InCl5 & BULL;H2O perovskites show an intense orange-red emission peak at 615 nm, ascribed to the P-3(1) to S-1(0) transition of Sb3+. The brightest luminescence of Sb3+:Rb2InCl5 & BULL;H2O was achieved by doping 40%Sb3+, with a high photoluminescence quantum yield (PLQY) of 62.1% and an external quantum efficiency (EQE) of 30.2%. Furthermore, the prepared Sb3+:Rb2InCl5 & BULL;H2O perovskite exhibits a distinguished thermal stability. At 150 & DEG;C, its PL intensity remains 68% of that measured at room temperature, with a high thermal activation energy of 0.184 eV. By combining Sb3+:Rb2InCl5 & BULL;H2O with a blue-emitting Eu2+:BaMgAl10O17 (Eu2+:BAM) phosphor, bright warm-white light with a color rendering index of 88 and a correlated color temperature of 3242 K was achieved. To sum up, the prepared Sb3+:Rb2InCl5 & BULL;H2O orange-red perovskites have the advantages of suitable excitation and emission peak positions, high emission intensity, high PLQY and EQE, excellent stability, and environmental friendliness, making them very attractive in the field of lighting and displays.