The Luminescent Behaviors and J-O Theory Analysis of Red Phosphor Ca1-Xgeo3:Xeu3+

Abstract

The luminescent material Eu3+-doped CaGeO3 has been synthesized using a high-temperature solid-state reaction technique. The crystal structure was analyzed using X-ray diffraction (XRD). The results showed that the samples belonged to the triclinic crystal system with the space group P[[EQUATION]]. The luminescent properties including photoluminescence excitation (PLE), Photoluminescence emission (PL) spectra, and lifetime, thermal stability, and diffuse reflectance spectroscopy (DRS) have been investigated. Under near-ultraviolet excitation at 390 nm, the phosphor emits red light with the highest intensity around 611 nm, which is dominated by the 5D0→7F2 electric dipole transitions. It indicates that Eu3+ is in the inversion center of the crystal. The concentration quenching occurs at about 6% doping from the concentration-dependent luminescence behavior. The energy transfer mechanism was analyzed to be mainly the energy transfer between neighboring ions. The thermal stability was 82.16% at 423 K. The chromaticity coordinates are located in the red and the color purity approaches 99%. Furthermore, the J-O theoretical results is used to confirm to the experimental result. It suggests that Ca1-xGeO3:xEu3+ is an effective red luminescent material for illumination and backlight display applications.

Keywords: CaGeO3:Eu3+, red phosphor, J-O theory