Synthesis and luminescence properties of Ca3Ga4O9:Eu3+: An efficient red-emitter for WLEDs

Abstract

Herein we report, an efficient red-emitting phosphor Ca3Ga4O9:Eu3+ (Eu3+: CGO) was synthesized via a conventional solid-state reaction technique. The physicochemical properties of the given oxide phosphors were investigated in terms of structural, elemental, compositional, and optical characteristics. The XRD study indicates that the compound CGO and Eu3+: CGO have been crystallized in an orthorhombic crystal system with the space group of Cmm2. The nature of the oxidative state of the elements and their compositional ratios were demonstrated by the XPS and EDS studies. The SEM analysis of the phosphor samples reveals micro flakes embedded in rod-like morphology. UV–Visible diffuse reflectance studies were performed to study the optical properties of the oxide phosphors. The optical energy gap value has been calculated using Kubelka-Munk equations and the values have a reducing trend due to the addition of the Eu3+ ion. The photo-emissive properties of the Eu3+ doped samples were illustrated by the PL analysis with the excitations of 465 nm and 394 nm (7F0 -5D2 and 7F0-5L6) respectively. The photometric (color coordinates, color purity, and correlated color temperature) parameters were also calculated. The Eu3+ doped samples show a high color purity within the range of 96.75–98.71%. The correlated color temperature (CCT) was also computed from the calculations which have the values from 1819 K to 1898 K. These results depict that the prepared Eu3+ ions doped oxide phosphor will be an efficient red-emitting candidate for white LED application.