Deposition and characterization of screen-printed porous multi-layer thick film structures from semiconducting and conducting nanomaterials for use in photovoltaic devices

Three-layer structures of thick (> 5 mu m) films of nanosized titanium dioxide, zirconium dioxide, and carbon have been screen-printed on a semi-production level for use in photosensitized photovoltaic devices. The films have been characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen adsorption/desorption. The rheology of the screen-printing pastes has been measured, and qualitatively matched to the quality of the resultant film. Three titanium dioxide candidates were evaluated for performance. At low light levels (< 300 lux, i.e., typical indoor light levels), photosensitized photovoltaic modules made from these screen-printed structures exhibited equal or superior performance to a commercially available amorphous silicon module.