Analysis of the structure and luminescence properties of Zn2GeO4:Eu3+ according to Judd-Ofelt theory

The preparation and characteristic of nanorod-like Zn2GeO4 doped with Eu3+ or zinc germanate (ZGO):xEu(3+) (x = 0 divided by 0.05), which was synthesized using the hydrothermal method, are described. The influence of Eu3+-doping ions on the structure and the optical properties of ZGO was also investigated. According to the photoluminescence spectra, ZGO:xEu(3+) nanophosphors gave a red emission due to the D-5(0)-> F-7(2) emission of Eu3+ ions. In accordance with Judd-Ofelt theory, the intensity parameters for f-f transitions from the emission and absorption spectrum were determined. At the D-5(0) excited state of Eu3+, total spontaneous emission probabilities (A(R)), lifetimes (tau(R)), branching ratios (beta(R)), and quantum efficiency (eta) were calculated. The ZGO:xEu(3+) (x = 0.02, 0.03, 0.04) phosphor showed the branch ratio beta (D-5(0)-> F-7(2)) > 60%, indicating that the phosphors prepared here have a promising potential as laser light. The sample with a concentration of 0.04Eu(3+) achieved the highest quantum efficiency of 84%, suggesting that it has potential light-emitting diode applications.