Chemical bath deposition of SnO2 and Cd2SnO4 thin films

A new approach of chemical bath deposition (CBD) of SnO2 thin films is reported. Films with a 0.2 μm thickness are obtained using the multi-dip deposition approach with a deposition time as little as 8–10 min for each dip. The possibility of fabricating a transparent conducting oxide layer of Cd2SnO4 thin films using CBD is investigated through successive layer deposition of CBD-SnO2 and CBD-CdO films, followed by annealing at different temperatures. High quality films with transmittance exceeding 80% in the visible region are obtained. Annealed CBD-SnO2 films are orthorhombic, highly stoichiometric, strongly adhesive, and transparent with an optical band gap of ∼4.42 eV. Cd2SnO4 films with a band gap as high as 3.08 eV; a carrier density as high as 1.7 × 1020 cm−3; and a resistivity as low as 1.01 × 10−2 Ω cm are achieved.