Ceramic Tiles with Photovoltaic Properties

The development of organic materials with photovoltaic properties should enable the production of polymeric solar cells with high conversion efficiency. Due to low production cost and conversion efficiency above 10%, organic solar cells have great potential to compete with inorganic photovoltaic cells. This work proposes the development and integration of ETA (extremely thin absorber) photovoltaic cells, based on titanium oxide films and nanostructured conductive polymer in ceramic tiles, with the purpose of increasing the available area for sunlight capture, normally limited to roofs, expanding it onto the lateral sides of buildings. The nanostructured TiO2 was obtained by sol-gel process from titanium isopropoxide, followed by supercritical CO2 extraction in order to obtain a nanostructured aerogel. The conductive polymer used was the poly-3.4 (ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) synthesized with iron III p-toluene sulfonate as an oxidizing agent. The materials were deposited layer by layer on a Cu electrode mounted on a ceramic tile piece, covered with glass containing a thin conductive layer of indium doped tin oxide (ITO). Transmission electron microscopy (TEM) revealed that the nanostructured titania aerogels exhibit particle sizes in the range of 2-5 nm. Preliminary studies have shown that the developed solar cell show a behavior typical of diodes (characteristic IxV curve) when subjected to different wavelength lamps (fluorescent and UV). Ceramic wall and roof tiles with photovoltaic properties, independently of the conversion efficiency, could serve as auxiliary energy sources to reduce expenses with conventional electricity.