Optical and Morphological Studies of Ga Doped Zno Nanocrystals

Abstract

ZnO undoped and doped nanocrystals with spherical morphology have been synthesized by à cost effective hydrolysis technique. X-ray diffraction analysis was carried out to evaluate the contribution of dopant ion lattice parameters. The crystallite size calculated is in good agreement with the TEM results. For pristine samples, PL is broad in nature with maxima at various positions in visible region of electromagnetic spectrum. The emission spectra of most ZnO sample show a near-band-edge line (λ=366 nm) followed by a deep level luminescence in lower energy regime (λ=453nm, 546nm and 634nm). In the present case, the higher energy band (366nm) is assigned to the occurrence of free excitons’ recombination through an exciton-exciton collision process. The Ga doped luminescence spectra, the emission peaks are at 364 nm,442 nm 544and 635nm. NBE emission had a decrement in the intensity along with shift towards lower wavelength and the 442 emission had a increase in intensity also the emission due to other intrinsic defects were depressed with Ga doping. This may be attributed to the decrease in particle size of doped samples.