Two-color Emission in Dy3+-activated CaZnP2O7 Pyrophosphate for White LED

Abstract: CaZnP2O7 pyrophosphate phosphor doped with Dy3+ ions was synthesized by modified solid-state reaction. The crystalline phases were recognized using X-ray diffraction. Surface morphology was studied by scanning electron microscopy. Furthermore, the chromaticity coordinates' values were estimated from the emission spectra of CaZnP2O7:Dy3+. The phosphor photoluminescence emission spectra were found to have an excitation at around 353 nm showing two distinguishing bands centered at about 482 nm (Blue) and 575 nm (Yellow) corresponding to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+, respectively. These phosphors have strong absorption in the near-UV region. The intact study reveals that the present phosphors are suitable for color converter using UV light as the primary light source, which can be used as a blue/yellow phosphor excited by the n-UV LED chip and mixed with other color emission phosphors to obtain white light. Keywords: Chemical synthesis, Luminescence, X-ray diffraction, Optical properties.