Antimony sulfide thin films in chemically deposited thin film photovoltaic cells

Antimony sulfide thin films of thickness approximate to 500 nm have been deposited on glass slides fi-om chemical baths constituted with SbCl3 and sodium thiosulfate. Smooth specularly reflective thin films are obtained at deposition temperatures from - 3 to 10 degrees C. The differences in the film thickness and improvement in the crystallinity and photoconductivity upon annealing the film in nitrogen are presented. These films can be partially converted into a solid solution of the type Sb2SxSe3 -(x3) detected in X-ray diffraction, through heating them in contact with a chemically deposited selenium thin film. This would decrease the optical band gap of the film from approximate to 1.7 eV (Sb2S3) to approximate to 1.3 eV for the films heated al. 300 degrees C. Similarly, heating at 300 degrees C of sequentially deposited thin film layers of Sb2S3-Ag2Se, the latter also from a chemical bath at 10 degrees C results in the formation of AgSb(S/Se)(2) with an optical gap of approximate to 1.2 eV. All these thin films have been integrated into photovoltaic structures using a US window layer deposited on 3 mm glass sheets with a SnO2:F coating (TEC-15, Pilkington). Characteristics obtained in these cells under an illumination of 850 W/m(2) (tungsten halogen) are as follows: SnO2:F-CdS-Sb2S3-Ag(paint) with open circuit voltage (V-oc) 470 mV and short circuit current density (J(sc) 0.02 mA/cm(2). SnO2:F-CdS-Sb2S3-CuS-Ag(paint), V-oc approximate to 460 mV and J(sc) approximate to 0.4 mA/cm(2); SnO2:F-CdS-Sb2Sx Se-3-(x)-Ag(paint), V-oc approximate to 670 mV and J(sc) approximate to 0.05 mA/cm(2); SnO2:F-CdS-Sb2S3-AgSb(S/Se)(2)-Ag(paint), V-oc approximate to 450 mV and J(sc) approximate to 1.4 mA/cm(2). we consider that the materials and the deposition techniques reported here are promising toward developing 'all-chemically deposited solar cell technologies. (C) 2007 Elsevier B.V. All rights reserved.