Red emission of copper aluminate synthesized 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 (tulsi) extract as a reducing agent (CAOT). The Bragg reflections of the as-formed product confirm the formation of a cubic phase with 3̄ 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.