Preparation and characterization of chemically deposited mixed bismuth sulphoselenide thin films

An electroless chemical method is used for the deposition of multilayer bismuth sulphoselenide thin films. Grediants used for the deposition are triethanolamine complex of bismuth, aqueous thioacetamide and sodium selenosulphite. Stoichiometric mixture of these ingredients were used for deposition of thin uniform and adhesive films on microslide at optimized temperature 55°C, pH 8.5 & time 2 hr. The substrates are kept rotating at a speed of 50 rpm. Thickness of mixed Bi 2 (S,Se) 3 is in between BiS 3 & Bi 2 Se 3 . The film have `n type conduction with high electric resistance. Optical study shows that the films are micro polycrystalline having optical band gap 2.2 for Bi 2 S 3 & 1.47 for Bi 2 Se 3 . The 'x' ray diffraction shows bismuth sulphoselenide is ternary mixed chalcogenide having a chemical formula. [Bi 2 (S,Se) 3 ].