Anti-Solvent Synthesis of Three-Color Indium-Based Halide Perovskite Microplate/Microcrystal Phosphors for High Color Rendering WLEDs

Lead-free halide perovskites are emerging as promising eco-friendly candidates for next-generation solid-state lighting because of their nontoxicity and availability for broad emission. Herein, a modified room-temperature anti-solvent precipitation method is developed to synthesize the Sb3+-doped, In-based, lead-free halide perovskites in microplate/microcrystal structure with different emission colors. The layered structure of InCl3 serves as the template for the growth of Cs2InCl5(H2O):Sb3+ microplate phosphors. Moreover, the presence of HCl not only improves the solubility of precursors, but also provides the acid etching effect. The resultant Sb3+-doped Cs2InCl5(H2O) microplate phosphors show bright yellow emission with photoluminescence quantum yield up to 92.4%. Furthermore, Cs3InCl6:Sb3+ and Cs2NaInCl6:Sb3+ are synthesized through the similar method, which displays the bright green and deep-blue emission, respectively. Subsequently, the proof-of-concept white light-emitting diodes (WLEDs) are fabricated based on Cs2NaInCl6:Sb3+ + Cs2InCl5(H2O):Sb3+ and Cs2NaInCl6:Sb3+ + Cs3InCl6:Sb3+ + Cs2InCl5(H2O):Sb3+ phosphors, which achieves high-quality white light with the color rendering index (CRI) of 91.6 and 95.4, respectively. The results greatly advance the development of lead-free halide perovskite phosphors synthesis, which may offer new possibilities for high CRI WLEDs fabrication.