Structural, Optical and Electrical Properties of Nanostructured CdS:CuS Composite Thin Films Grown by CBD Method

Synthesis of nanostructured composite chalcogenide materials have been the subject of much interest in basic research because of their photovoltaic applications. The ternary composite semiconducting thin films of CdS:CuS were successfully deposited onto glass substrates at room temperature by Chemical Bath Deposition (CBD) method using cadmium acetate, cupric acetate and sodium thiosulphate in acidic medium. The films were characterized by using X-ray diffraction, scanning electron microscopy, Fourier transform infrared (FTIR) spectrum, optical absorbance, dc electrical resistivity measurements and thermo-emf techniques.Theas deposited CdS:CuS composite thin films are polycrystalline in nature with hexagonal phase of CdS and CuS with average crystallite size of 23 nm.The optical band gap and activation energy of CdS:CuS thin film is found to be 2.77 and 0.03 eV respectively. The electrical resistivity at 373 K temperature was found to be of the order of 6.87 Ω-cm and it decreases as temperature increases indicating its semiconducting nature.The thermo-emf measurement conforms p-type conductivity of CdS:CuS.The water angle contact measurement conforms hydrophilicnature of CdS:CuS thin films.