Progress towards blue emitting MgO-ZnO-Ga2O3 nanocomposites synthesized by bio mediated route.

MgO-ZnO-Ga2O3 nanocomposites are synthesized by solution combustion method using Aloe Vera gel as a reducing agent to increase the efficiency of blue emission. The appearance of Bragg reflections corresponding to MgO, ZnO and Ga2O3 clearly indicates the formation of nanocomposites. The surface morphology consists irregular shape and sized NPs. The Energy dispersive X-ray analysis confirms the purity of the sample. The band energy gap was tuned to 3.1 eV. The Photoluminescence excitation and emission spectra was discussed and compared it with emission spectra of individual oxides as well as with other reported blue emitted nanophosphors. Further, the chromaticity coordinates and Color correlated temperature coordinates clearly confirms their warm blue emission. Further, the powder dusting method was employed to collect the latent fingerprints on the pores and non-pores surfaces. The synthesized MgO-ZnO-Ga2O3 nanocomposites exhibits well-resolved ridge patterns that can be used to identify latent finger prints with clarity. From all these results, the present synthesized MgO-ZnO-Ga2O3 nanocomposite might find an application in display technology as a blue nanophosphor material and for latent finger print detection in crime investigation.

Red emission of copper aluminate synthesized via chemical and bio-mediated routes.

For the first time, copper aluminate nanoparticles (NPs) are synthesized by a combustion method using urea as a fuel (CAOU) and Ocimum sanctum (tulsi) extract as a reducing agent (CAOT). The Bragg reflections of the as-formed product confirm the formation of a cubic phase with Fd3̄m space group. The crystallite size, crystallinity and other structural parameters are discussed. The surface morphology of CAOU is agglomerated in nature whereas that of CAOT is hexagonal in shape. The smaller crystallite size CAOT NPs show a higher energy band gap. The photoluminescence (PL) analysis excited at 302 nm shows that the CIE coordinates fall in the red region. The oxygen defects are mainly responsible for the PL emission. The CCT coordinates confirm that both CAOU and CAOT NPs can find an application in warm light emitting diodes.