The growth of tin sulfide (SnS) films with large surface area have been accomplished. A uniform nanowall SnS thin film over the entire substrate was achieved by using, in economic chemical bath deposition method and observed by scanning electron microscopy. Microstructure. phase. confirmation, and optical properties were investigated. X-ray diffraction pattern and transmission electron microscopy revealed that the till sulfide film by chemical bath deposition exhibited polycrystalline orthorhombic structure. The optical absorption coefficient was high, more than 10(4) cm(-1), which is beneficial for a photovoltaic device, An optical indirect bandgap of SnS film was obtained to be 1.19 eV. The effect of SnS film thickness on bandgap was also investigated. When the thickness was small. in the range of less than 500 Inn. the bandgap of SnS film increased with the increase of thickness. When the thickness was large, in the range of more than 500 nm. the bandgap slightly decreased with the increase of thickness. The photoconductivity increased with the Increase of film thickness for the nanowall SnS thin films. (C) 2008 The Electrochemical Society.