Synthesis, structural and optical properties of Er doped, Li doped and Er plus Li co-doped ZnO nanocrystallites by solution-combustion method

Pure zinc oxide (ZnO) and 2 mol% of Er, 1 mol% of Li individually doped and Er + Li co-doped ZnO nanopowders were synthesized by auto-combustion method. Crystal structure and grain size were characterized by X-ray diffractometer and found that all synthesized samples have hexagonal wurtzite crystal structure. Scanning electron microscope (SEM) and Transmission electron microscope (TEM) studies were used to determine the morphology and size of the nanocrystallites. A UV-VIS measurement shows four absorbance peaks in the visible regions and the band gap is slowly blue shifted after annealing at 800 degrees C. The presence of Er, Li and the hexagonal wurtzite structure was confirmed by FT-IR studies. FT-Raman spectroscopy has been employed to study the crystalline quality and structural disorders. (C) 2013 Elsevier B.V. All rights reserved.