CuO nanostructured thin films synthesised by chemical bath deposition on seed layers deposited by successive ionic layer adsorption and reaction and chemical spray pyrolysis techniques

Abstract

One dimensional (1-D) CuO nanostructures have been synthesised by a simple, low cost and facile chemical bath deposition (CBD) method on seed layers deposited by successive ionic layer adsorption and reaction (SILAR) and chemical spray pyrolysis (CSP) techniques. During the CBD process, ammonia solution and ethylene glycol were used as complexing and surface assisting agents respectively. The overall images of the nanostructures resemble some reed-like shrubs and dandelions growing on a lawn of grass-like nanostructures. All the X-ray diffraction peaks observed were indexed to pure monoclinic phase of CuO. The two main diffraction peaks located at around 2θ equals to 35.5° and 38.6° corresponds to (1−11) and (111) planes of monoclinic CuO respectively. The presence of characteristic Ag and two Bg primary Raman active modes in the Raman spectra confirmed formation of CuO. The broadening and shift in Raman peaks in SILAR/CBD films relative to the CSP/CBD film may be attributed to strain in the lattice. Optical transmission spectra revealed that the samples were mainly absorbing in the visible and UV spectral regions with a blue shifted optical band gap.