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

Abstract

The preparation and characteristic of nanorod‐like Zn2GeO4 doped with Eu3+ or zinc germanate (ZGO):xEu3+ (x = 0 ÷ 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:xEu3+ nanophosphors gave a red emission due to the 5D0→7F2 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 5D0 excited state of Eu3+, total spontaneous emission probabilities (AR), lifetimes (τR), branching ratios (βR), and quantum efficiency (η) were calculated. The ZGO:xEu3+ (x = 0.02, 0.03, 0.04) phosphor showed the branch ratio β (5D0→7F2) > 60%, indicating that the phosphors prepared here have a promising potential as laser light. The sample with a concentration of 0.04Eu3+ achieved the highest quantum efficiency of 84%, suggesting that it has potential light‐emitting diode applications.