Inclusion of polyaniline in electrodeposited bismuth sulphide thin films: Synthesis and characterization

Structural, electrical and optical properties of polyaniline (PAni) doped Bi₂S₃ composite thin films prepared by electrodeposition method are reported. X-ray diffraction pattern indicates its polycrystalline nature and crystallite size increases with increase in the concentration of PAni. FTIR studies reveal that the dopant PAni has affected the absorption phenomenon in the IR region of the Bi₂S₃ thin films. The optical band gap energy is found to be 1.91 eV for as-deposited Bi₂S₃ thin film and it decreases with increase in the concentration of PAni. The morphology of the doped films changes due to the addition of PAni. Electrical studies indicate that the conductivity increases with increase in the concentration of PAni. The conduction results from a hopping due to localized states in the temperature range 300–358 K. Above 358 K, the conduction process is explained by the traps at grain boundaries of partially depleted grains.