Lead-free perovskite variant Rb2SnCl6:Te based phosphor-sapphire composite for high-power laser-driven lighting

Lead-free perovskite variants have attracted wide interest because of the lead-free feature and broadband emission originated from self-trapped exciton (STE), which show great advantages in lighting applications. Especially the tetravalent Te-doped A 2 B(IV)X 6 perovskite variants, which have efficient excitation in the blue range and strong emission in the yellow region as well as high photoluminescence quantum yield , is particularly suitable for solid-state lighting. Despite these fascinating properties, it is still not suitable for high-power illumination due to its poor thermal resistance and severe light saturation feature at high laser power density. Herein, we develop a lead-free perovskite variant Rb 2 SnCl 6 :Te based phosphor-sapphire composite (PSC) fused with low-melting glass through a simple screen-printing and sintering process . The as-prepared PSC shows yellow-green emission at 570 nm, due to the combination of Te luminescent center and Jahn-Teller-like STE, and exhibits a high thermal conductivity of 37.06 W m −1  K −1 . Benefitted from the high thermal conductivity of the sapphire substrate , the PSC exhibits the great improvement in light saturation behavior, heat dissipation, and chromaticity stability withstand the high-power blue laser , compared to Rb 2 SnCl 6 :Te phosphor, finally contributing to an excellent PLQY of 70.3%. In addition, by combining the PSC with the blue laser, a warm white light with a CIE chromaticity coordinate of (0.368, 0.344), and a correlated color temperature of 4129 K is achieved. These results demonstrate that this simple and low-cost fabrication method is expected to be widely used for various phosphors and the PSC can own excellent application prospects in high-power laser-driven lighting.