Rare earth-based Cs2NaRECl6 (RE = Tb, Eu) halide double perovskite nanocrystals with multicolor emissions for anticounterfeiting and LED applications

Abstract

Metal halide double perovskites are the promising alternative to lead-based perovskites. Especially, rare earth (RE)-based halide double perovskites have attracted much attention due to the unique optical properties. As RE3+ ions could be served not only as the component of matrix, but also as the luminescence centers, the chemical composition of RE-based halide double perovskites can be simplified and tunable luminescence could be achieved. In this work, Cs2NaRECl6 (RE = Tb, Eu) halide double perovskite nanocrystals were synthesized by hot injection method. Cs2NaRECl6 nanocrystals exhibit not only the intrinsic host emission, but also the characteristic emissions of RE3+ ions. Furthermore, the excitation-wavelength-dependent multicolor emissions of Cs2NaRECl6 nanocrystals makes them great potential for anticounterfeiting applications. Multicolor LEDs devices based on various components of Cs2NaRECl6 could be obtained, which providing the promising candidates for optoelectronic applications.