Hydrothermal Synthesis and Characterization of Undoped and Eu-Doped ZnGa[sub 2]O[sub 4] Nanoparticles

Nanoparticles of and Eu-doped were hydrothermally synthesized varying the process parameters, such as the volume ratio of the cation precursor solutions, temperature and time of growth, and dopant concentration. The nanoparticles were structurally characterized by X-ray diffraction, high-resolution transmission electron microscopy, and selected-area electron diffraction. The studies confirmed the formation of spherically shaped nanoparticles with the standard spinel structure. Photoluminescence (PL) studies show that Eu-doped nanoparticles exhibits a sharp red luminescence due to the intra-4f transitions of ions at an excitation of . Luminescence quenching is observed in the nanoparticles at higher Eu concentration. The room-temperature PL measurements of pure nanocrystals monitored at an excitation wavelength of gave a peak-shaped spectrum instead of the normally observed bell-shaped spectrum of bulk . The bandgap of the nanoparticles is blueshifted compared to the bulk material due to quantum confinement effects. Incorporation of Eu in the nanoparticles was confirmed by inductively coupled plasma atomic emission spectroscopic studies.