Influence of growth temperature on the physico-chemical properties of sprayed cadmium oxide thin films

Transparent conducting cadmium oxide (CdO) thin films have been deposited onto the soda-lime glass (SLG) substrates using a facile and cost-effective spray pyrolysis (SPT) technique. The films have been deposited at various substrate temperatures ranging from 250 to 400 °C in steps of 50 °C. The influence of substrate temperature on structural, morphological and electro-optical properties of CdO thin films has been investigated. Thermo-gravimetric analysis (TGA) study indicates the formation of CdO by decomposition of cadmium acetate after 250 °C. The X-ray diffraction study reveals that all samples are polycrystalline with major reflex along the (111) and (200) planes, manifested with the homogeneous distribution of roughly spherical clusters all over the substrate of varying grain size.The optical study shows band gap ranging between 2.3 and 2.5 eV. The Hall effect measurement indicates that the resistivity decreases from 2.43×10−3 to 0.99×10−3 Ω cm while carrier concentration increases from 2.61×1020 to 5×1020/cm3 and mobility lies in the range of 8.26–12.55 cm2/V s.