Photoluminescence Properties and Quantum Efficiency of Eu~(3+)/Mn~(2+)-Doped ZnMoO_4 Red Phosphor

摘要

In this work, fabrication and characterization of a nano-structured rare-earth-doped ZnMoO_4 will be reported. Photoluminescence properties and quantum efficiency of the rare-earth-doped ZnMoO_4 with different dopant concentrations have been investigated. These samples were synthesized by sol-gel method. Lattice structure of the fabricated samples was characterized by X-ray powder diffraction (XRD); absorption spectrum was performed on UV-2600 photo spectrometer; PL excitation and emission spectra were recorded by Fluorescence Spectrometers; quantum efficiency was measured by an integrating sphere photoluminescence (PL) system. The results showed that the optimized doping concentration of Eu3+ was around 10 mol% for the highest quantum efficiency at 616 nm emission peak and 465 nm excitation peak. The highest internal quantum efficiency was 91% at low power density excitation (around 50 uW/mm2). Introduction of Mn~(2+) to Eu~(3+)-doped ZnMoO_4 lead to reduced quantum efficiency and electronic lifetime, which can be attributed to defects inside the crystal lattice and energy transfer from Eu~(3+) to Mn~(2+) (more non-radiative transition occur).