Higher Intrinsic Quantum Yield of Eu3+-Doped Zn2sio4 Obtained by Sol-Gel Process, Calculated by Judd - Ofelt Theory

Abstract

The sol-gel process allows the obtaining of Eu3+-doped Zn2SiO4with 1 mol% with different molar ratios between Zn2+ and Si4+. The materials reported here were obtained with a resistive furnace at 600, 900, 1000 and 1100°C degree, during 2 h. All the materials exhibited an intense photoluminescence emission with bands assigned to the Eu3+ transitions. Among the materials studied, the samples containing 70 and 80% of Si4+, exhibited higher Eu3+ lifetimes values. The predominance of the quartz phase decreases micro deformations and the location of the Eu3+ ions in higher symmetry sites, reducing the intensity of the photoluminescent materials. The increasing of annealing temperature contributes to the detrimental lifetime and luminescence materials due to the location of the Eu3+ in the site of high symmetry. Through Judd-Ofelt theory was possible to obtain higher values of intrinsic quantum yield (QLn Ln) between 32 and 66% dependent on the temperature of heat-treatment, in comparison with the same material reported in the literature. Keywords: Orthosilicates; Photoluminescence; Rare Earth; Europium;