Publication

Abstract : In the present report, a series of intense red light emitting SrZrO3:Eu3+ nanopowders were fabricated via low-cost eco-friendly hydrothermal route using Aloe vera gel as surfactant. Upon utilizing the powder X-ray diffraction (PXRD) method the phase of the prepared nanopowders were evaluated. Pure single-phase tetragonal structure was observed from the PXRD results with no additional impurity peaks. The energy band gap of the fabricated powders was calculated by diffuse reflectance spectra (DRS) and found to be around 3.98 – 4.27 eV. High resolution scanning electron microscope (SEM) was utilized to study the morphological behavior of the prepared powders. Honeycomb-like structures were observed from the SEM micrographs. The particle size was evaluated by transmission electron microscopy (TEM) and observed to be ∼ 42 nm. The interplanar distance was found to be around 0.32 nm. Photoluminescence properties were systematically studied in detail. The phosphors were successfully excited at 395 nm NUV light, producing intense red characteristics emission. The emission peaks were centered at 585 nm (5D0→7F1), 613 nm (5D0→7F2) and 648 nm (5D0→7F3). The photoluminescent concentration quenching was noticed beyond 5 mol% Eu3+ ion doping content. The dipole-dipole interaction resulting in cross relaxation was found to be the principal cause of concentration quenching mechanism. The color features such as Commission International de I'Eclairage (CIE) and correlated color temperature (CCT) were studied in detail. The optimized chromaticity coordinates were estimated to be (0.67, 0.32), which falls in the intense red region. The average CCT value obtained was 4328 K. The color purity was observed around ∼ 88%. In addition, the average internal quantum efficiency was calculated, and it was found to be 48%. The prepared powders exhibit excellent luminescence properties, quantum efficiency and high color purity. The obtained results indicate the possibility of the present powders in the fabrication of the red-light emitting diode applications.