A heterostructured SnO2–TiO2 thin film prepared by Langmuir–Blodgett technique

• Thin film of SnO2–TiO2 heterostructure was prepared by Langmuir–Blodgett technique.
• The decomposition temperature of LB film was 600 °C to form oxide thin films.
• Structural and electrical properties were studied by XRD, DC and AC impedance studies.
• Increase in photocurrent was observed in heterostructure film in presence of visible light.

SnO2–TiO2 heterostructure films were prepared through Langmuir–Blodgett (LB) route. LB films of octadecyl amine (ODA)–titanyl oxalate multilayer deposited on Si (100) and decomposed at 600 °C showed rutile and anatase phases of ultrathin TiO2 film. Subsequently, multilayer LB film of ODA–stannate deposited on the pre deposited TiO2 film after decomposition at 600 °C resulted in thin SnO2 films on the TiO2 thin film. The phase analysis of the SnO2–TiO2 film showed cassiterite phase of SnO2 as well as the rutile/anatase mixture of TiO2 indicating a SnO2–TiO2 heterostructured film. Surface morphology of the pure TiO2 film and SnO2–TiO2 film were analyzed by using AFM. Electrical characterization by AC impedance analysis suggested SnO2–TiO2 heterostructure formation. DC current voltage measurement showed increase in photocurrent indicating visible light absorption and efficient charge separation under the sunlight type radiation.