Improving the luminous properties of deep red emitting K2SiF6:Mn4+ phosphor by coupling with g-C3N4 for warm white LED

Abstract K2SiF6:Mn4+/g-C3N4 (KSF/g-C3N4) composite phosphors were directly synthesized by pretreatment of raw materials. This way avoided the damage to the luminescent properties of phosphors compared with the conventional method for preparing composites. The structure, morphology, and composition of K2SiF6:Mn4+/g-C3N4 samples were investigated by X-ray Diffraction (XRD), Energy Dispersive Spectrometer (EDS) and Scanning Electron Microscope (SEM). Fluorescence and UV–Vis absorption spectra have also been measured to study their optical properties. By combine with g-C3N4, the absorption intensity of composite is greatly increased in the UV–Vis range, while its luminous intensity is also significantly enhanced. This is owing to g-C3N4 increases the absorption capacity of the phosphor for UV–Vis light, and the overlap of the two emission spectra and excitation spectra promoted energy transfer to K2SiF6:Mn4+ phosphors.