IMPORTANCE OF THE COLOR TEMPERATURE IN COLD WHITE LIGHT EMISSION OF Ca2MgSi2O7: Dy3+ PHOSPHOR

Abstract

A promising candidate of white light-emitting (Ca2MgSi2O7: Dy3+) phosphor was successfully synthesized via traditional high-temperature solid-state synthesis technique using boric acid (H3BO3) as a fuel. The synthesized material sample was characterized with the help of powder X-ray diffraction (PXRD), FT-IR (Fourier Transform Infra-red) Spectroscopy, FESEM (Field Emission Scanning Electron Microscopy) and PL (Photoluminescence) spectra. Using the Debye-Scherer formula and UDM method, the crystallite size and crystal lattice strain were evaluated, respectively. Photoluminescence (PL) properties (both excitation & emission spectra) for the prepared phosphor were systematically investigated in detail. Photoluminescence spectra were revealed that the strong transition of spectral emission lines centered at 484nm (blue), 578nm (yellow) and weak transition of spectral emission lines centered at 615nm (red) wavelength. These peaks were assigned to following transitions (4F9/2 → 6H15/2,13/2,11/2), which are responsible for the (f→f)  transitions from the ground  level (lower energy state) to excited level (higher energy state) in the 4f9electronic configuration of dopant [Dy3+] ions. CIE color chromaticity coordinates and Color Correlated Temperature (CCT) of synthesized Ca2MgSi2O7: Dy3+ phosphor sample is well suited for the generation of cold white light emission with a CIE coordinate value of (X = 0.31, Y = 0.32) and CCT value also calculated as 5167K. Here upon, it is highly applicable to be a novel hopeful phosphor for cold WLEDs.