Novel transparent conducting sol–gel oxide coatings

Abstract

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 Zn 2SnO 4, Zn 3In 2O 6 and Zn 5In 2O 8 and X-ray amorphous ZnSnO 3 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. ZnGa 2O 4 and GaSbO 4 coatings showed no electrical conductivity. For Zn 2SnO 4 coatings, a restricted crystallite growth was observed probably due to phase segregation effects. Electrical properties of coatings in the system ZnO–In 2O 3 were interpreted on the basis of the percolation theory.