An electroplated substrate, characterized by a substantially reduced number of surface defects, for the fabrication of thin film electronic devices. The substrate is prepared in an electroforming process by electroplating onto and removing a metallic layer from the surface of a specifically prepared, substantially defect-free mandril. The substrate may be provided with a preselected surface finish by either (1) texturing the mandril or (2) controlling the parameters of the electroplating process to control the morphology of the deposit. The substrate is especially adapted for the fabrication of thin film photoresponsive devices which incorporate specular or diffuse back reflectors, since the texture may be controlled to provide for the appropriate type of reflectivity. Large area, thin film semiconductor devices incorporating the electroplated substrate are readily scribed to form electrically isolated small area segments for the fabrication of modules, arrays and the like.