The chemical deposition of Bi2S3 thin films on glass substrates modified by treatment with solutions of 3-mercaptopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane is described. Such treatment helps prevent the peeling of thin films, a problem which is otherwise encountered in the chemical deposition process. Uniform thin films having thicknesses up to 0.32 mu m were obtained on the modified surfaces. X-ray photoelectron spectroscopy was employed to demonstrate that silanization takes place at the surfaces of the glass substrates. The relative atomic concentrations of nitrogen or sulfur on these surfaces increase with the time of immersion in the silanizing solutions. X-ray diffraction patterns of air-annealed Bi2S3 thin films were obtained. Optical transmittance and photoconductivity were measured and compared with those of the thin films deposited on untreated glass substrates. It was found that the thin films deposited on the silanized substrates were stable at 200 degrees C and maintain their original physical characteristics.