Novel transparent conducting sol–gel oxide coatings

This work focuses on the preparation of novel ternary transparent conducting oxide coatings on glass by the sol–gel method. The coatings were deposited by spin-coating from solutions of appropriate metal precursors and heat-treated at different heat-treatment procedures. An increase in electrical conductivity was achieved by a final forming gas treatment. Best electrical and optical properties have been obtained for coatings of crystalline Zn2SnO4, Zn3In2O6 and Zn5In2O8 and X-ray amorphous ZnSnO3 with resistivities in the order of 10− 2–10− 1 Ω cm, an average transmission in the visible of 85% and an average surface roughness of ∼ 1 nm. ZnGa2O4 and GaSbO4 coatings showed no electrical conductivity. For Zn2SnO4 coatings, a restricted crystallite growth was observed probably due to phase segregation effects. Electrical properties of coatings in the system ZnO–In2O3 were interpreted on the basis of the percolation theory.