Sol-gel dip coated CdO:Al films

Cadmium oxide (CdO) films were deposited by the sol-gel dip coating using acrylamide route. The films were doped with different concentrations of gallium in the range of 500-3500 ppm. X-ray diffraction studies indicated the films to possess cubic structure. The grain size, strain, lattice parameter, dislocation density, texture coefficient were estimated from the XRD pattern. The texture coefficient varies in the range of 0.16-0.61 for the different peaks. Optical transmission measurements indicated direct and indirect band gap values of 2.59 and 2.06 eV. Electrical conductivity of the undoped film was 0.5 x 103 mho cm-1, after doping with aluminium, the conductivity increased to 1.5 x 103 mho cm-1. Mobility decreased from 250 to 35 cm2 V-1 s-1 with an increase of Al concentration. Solar cell studies made on the Si/CdO cells under an illumination of 90 mW cm-2 yielded an Voc of 0.62 V, Jsc of 16 mA cm-2, ff = 0.76 and η = 9.55%.