Effect of Co-doping on Structural, Morphological, Optical and Electrical Properties of p-type CuO Films

In the present work, we studied the effect of cobalt (Co) doping rate between 2 % and 6 % on the structural, optical and electrical properties of thin films from copper acetate (Cu(CH3COO)2·H2O) produced by spray pyrolysis. The results obtained during the various characterizations carried out (Raman, contact angle, UV-Visible and the Hall effect) show that our films have a monoclinic structure with the presence of a single CuO phase. The measured contact angles are less than 90° for the CuO undoped, CuO:2 %Co and CuO:4 % Co confirming the hydrophilic character of the films, as well as the 6 % doped film shows the hydrophobic character with a contact angle greater than 90° (θ = 97.41°). An improvement of the absorption by the reduction of the transmittance for the films doped with 2 % Co, 4 % Co and 6 % Co with a low value of the transmission obtained in this work for the CuO:6 % Co film equal to 7.34 %. A decrease in the values of the optical gap as a function of cobalt doping with a low value equal to 1.66 eV found for the thin layer of CuO:6 % Co. The electrical analysis shows that the conductivity increases with the addition of cobalt to the CuO with a high value for the film doped with 6 % (σ = 7.246 x 10 – 1 (Ωxcm) – 1). So, CuO-doped 6% cobalt has good physical characteristics which allow it to be used as a layer absorbing solar radiation in thin-film solar cells.