Structural and optical properties of spray-pyrolysed Bi2S3 thin films

Thin layers of bismuth trisulfide (Bi2S3) have been prepared for the first time by the spray pyrolysis method on glass substrates from bismuth chlorid e (BiCl3) and thiourea (CS(NH2)(2)) solutions with a concentration of 0.2 M . Films deposited on substrate at 570 K have a polycrystalline structure wi th crystallites size in the order of 120 Angstrom. X-Ray characterization b y grazing angles diffraction (GAD at 0.4 and 2 degrees shows crystalline st ructures in surface and volume. Diffraction spectra of these films are inde xed in the orthorhombic system. Studies of optical absorption in the energy range 1.5-4 eV indicate an optical gap of 1.66 eV. The Hall effect measure ments indicate a carrier concentration of n = 3.45 x 10(17) cm(-3). (C) 199 9 Elsevier Science S.A. All rights reserved.