White-Light-Emitting Control via Lead-free Perovskite Material

Abstract

In recent years, the emerging lead-free halide perovskites are attracting great attention in the field of the optical detection and luminescence due to its inherent strong light absorption and high balanced carrier on transmission characteristics. This experiment attempts to explore the way of grinding to prepare the white light emitting materials that does not contain lead. Low dimensional lead-free copper-based halide luminescent materials are prepared by controlling the molar ratio of a series of lead-free perovskite materials Cs3Cu2I5 and CsCu2I5. As-synthesized powder samples are characterized by powder X-ray diffraction (XRD), photoluminescence spectrum (PL), photoluminescence excitation spectrum (PLE) and photoluminescence quantum yield (PLQY) and other characterization methods. We successfully prepare the white powder sample by controlling the molar ratio of reactants (CsI:CuI=1:3). We measure the Commission Internationale de l’Eclairage (CIE) chromaticity coordination of PL spectra for the samples which can be regulated by the ratio of reactants. Moreover, it is demonstrated that acetone can effectively promote the reaction of reactants. These findings make this material be a stable and environmentally friendly white luminescent material, which has the potential to be used in white LED applications.