Sb3+/Sm3+ co-doped Cs2NaGdCl6 double perovskite: A promising candidate for the single-component based WLED lighting with high quality

The realization of white light emission in a single matrix has always been a problem that researchers are working on. As a new luminescent material, lead-free halide double perovskites(DPs) has made this idea possible due to its wide emission spectrum. However, the drawback of low photoluminescence quantum yield (PLQY) originated from self-trapping excitons (STEs) has seriously hindered their development and applications. In this study, we focused on Cs 2 NaGdCl 6 (CNGC) DP nanocrystals, and enhanced the STEs, corresponding to the much developed blue emission intensity at about 470 nm by introducing Sb 3+ , associated with the significant increase of PLQY up high to 90.09 % at the optimal doping level. To achieve the all-spectrum white light within this phosphor, the lack wavelengths at green and red region has to be compensated and Sm 3+ is an ideal candidate. Therefore, the spectrum of CNGC:Sb 3+ was expanded via further co-doping Sm 3+ and consequently the emission color is tuned from blue to white contributed by the effective energy transfer from STEs to Sm 3+ . Finally, an UV-excited LED device based on CNGC:Sb 3+ /Sm 3+ phosphor was fabricated and strong white light emitting was achieved. The CIE of the device coordinates in the cold white region of (0.33, 0.30), associated with the color temperature of 5794 K. All the results indicate that the CNGC:Sb 3+ /Sm 3+ phosphor possesses great potential in the application of full spectrum lighting as prominent single-component white light emitter.