LAUSR

Abstract The one-dimensional structure TiO2/Bi2S3 composite films can be used as the photo-anode in the thin film solar cells. Due to its advantages of wide optical absorption range and relatively simpler fabrication progress, the composite film TiO2/Bi2S3 show important value in the photovoltaic field. The composite films were prepared with the simple two step hydrothermal method. The composite film TiO2/Bi2S3 was treated under different annealing temperatures (200 °C, 300 °C, 350 °C and 400 °C). The effect of the annealing temperature on morphology, microstructure, crystallite size, band gap, optical and electrical properties of the resultant material have been investigated. After annealing treatment, the photocurrent density of the composite film was significantly increased. With the increase of annealing temperature, the change tendency of optical absorption and photocurrent density show the same trend, both of them first increase and then decrease. The TiO2/Bi2S3 composite film annealed at 350 °C showed the best photoelectric properties. The Bode-Phase plots indicated the electron lifetime in TiO2/Bi2S3 composite film with 350 °C annealing treatment is about four times than that in as-deposited TiO2/Bi2S3 film. The annealing treatment can promote the secondary growth of Bi2S3 crystals in the composite film TiO2/Bi2S3, increase the light absorption, improve the utilization of sunlight, and thus increase the photocurrent density.