Efficient near-infrared emission and imaging of lead-free double perovskite Cs2TeCl6 by Mo4+ doping

In this work, we successfully synthesized a novel lead-free perovskite material Cs 2 TeCl 6 : xMo 4+ (x = 0.02,0.06,0.1,0.2) and conducted in-depth research on its near-infrared emission characteristics. The morphology of the material was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results confirmed that the synthesized Cs 2 TeCl 6 : xMo 4+ exhibited excellent crystallinity and high phase purity. And it exhibits efficient luminescence performance in the near-infrared region, with a maximum emission wavelength of 900 nm and a full width at half maximum of 100 nm. The photoluminescence quantum yield (PLQY) in the near-infrared region (750–1100 nm) measured at an excitation wavelength of 450 nm is as high as 29 %. The temperature-dependent (80–480K) near-infrared PL spectra also exhibit good thermal stability at low and high temperatures. Near infrared phosphor converted LEDs (pc-LEDs) made from this material exhibit excellent stability in the range of 100 mÃ500 mA. The pc-LEDs based on Cs 2 TeCl 6 : 0.1Mo 4+ material exhibit efficient near-infrared emission in the near-infrared region, demonstrating excellent performance in applications such as venous photography, night vision and drug impurity detection. In addition, the excellent performance of this material not only provides new insights for the application of perovskite materials in near-infrared luminescence, but also provides important theoretical and experimental basis for the development of new and efficient near-infrared luminescent materials.