Structural and Optical Properties of ZnO and Co Doped ZnO Thin Films Prepared by Sol-Gel

Abstract

We report on ZnO films doped with different Co concentrations (0, 0.5, and 1 wt%) prepared by sol-gel technique in association with dip-coating onto glass substrates. Zinc acetate dehydrate, cobalt acetate, mono ethanolamine were used as starting materials, as well as solvent and stabilizer, respectively. Nanostructured polycrystalline ZnO thin films with different concentrations of Co doping (0, 0.5, and 1 wt%) are prepared for the first time by the sol-gel method and annealed at 500• C for 1 h. The surface morphologies of the ZnO thin films deposited on glass substrate with different concentrations were evaluated by atomic force microscopy. The optical absorption of the films showed a blue shift of the band gap. The photoluminescence signal of the thin films of undoped and Co-doped ZnO presents different bands in the visible region. The electrical conductivity of the sample with 0.5%Co was found to be 4.62 (Ω C m) −1 .

Film Thickness Effect on Properties of Co-ZnO Thin Films Prepared by Sol-Gel Method

“…We noticed that all samples have nanometric crystallite sizes. This result is in good agreement with literature data [13,14].…”

The role of cobalt doping in tuning the band gap, surface morphology and third-order optical nonlinearities of ZnO nanostructures for NLO device applications

“…[9][10][11] The inuence of Co into the host ZnO, the size of the nanocrystals were varied and could be the conducting layers for numerous applications such as solar cells and transparent display devices 12 In particular, Zn 1Àx Co x O as a TCO lm exhibits numerous advantages over ITO since both Zn and O are abundant and non-toxic elements. 13 Several deposition techniques such as chemical vapor deposition, 14 magnetron sputtering, 15 pulsed-laser deposition, 16 atomic-layer deposition, 17 sol-gel 18 and spray pyrolysis 19 have been used to prepare ZnO lms. Spray pyrolysis (SP) is wellsuited for the deposition of large-area thin lms and is very useful for optoelectronic device applications.…”

Colloidal synthesis and characterization of nanostructured pure ZnO and In doped ZnO thin films

“…2), indicates a deterioration of the crystalline quality of the lm. This observation has con rmed by the XRD spectra, which may be due to the formation of stresses caused by the difference in ion size between zinc (r Zn +2 = 0.074nm) and dopant (r In +3 = 0.081nm), and dopant segregation at grain boundaries for high doping concentrations, which in uences structure growth [12,19].…”

“…This change can be attributed to the micro deformations produced by the residual stress. The substitution of Zinc by Indium increases the degree of distortion and internal tensile stresses in the ZnO lattice, which in uences the quality of the crystal [19].…”