Characteristics of dye-sensitized solar cells with carbon nanomaterials

Dye-sensitized photovoltaic cells consisting of a layered structure have been developed for 20 years and they are a basis for the new development trend of photovoltaics. One of the examined aspects of their application is building-integrated photovoltaics. Dye-sensitized photovoltaic cells (DSSCs) were developed by Michael Grätzel and Brian O'Regan in 1991 and have been intensively examined ever since. Because of their low production costs, easy transfer, the relatively high efficiency of the photon conversion to the current and an easy production technology, dye-sensitized cells might represent an alternative to silicon cells. Basically, a dye-sensitized photovoltaic cell consists of five elements: a mechanical base covered with a layer of transparent conductive oxides (TCOs), a semiconductor film, e.g., TiO₂, dye absorbed on the semiconductor's surface, an electrolyte including a redox carrier, and a counter electrode suitable to regenerate a redox carrier, e.g., platinum. As part of this work we produced dye-sensitized solar cells. First, the glass with transparent conductive oxides was thoroughly cleaned. Then, the glass with TCO was coated with a layer of TiO₂ using the doctor-blade technique, and fired in a furnace at 450 °C. The plate prepared in this way was then sensitized in a ruthenium-based dye. The counter electrode was obtained by applying it on the glass with TCO carbon nanomaterials, including graphite, carbon black and carbon nanotubes. The photo-anode and the counter electrode were combined and between them was injected the redox electrolyte. This paper provides an analysis of the microstructure and electrical properties of nanostructural coatings with the carbon nano-element of the integrated dye-sensitized photovoltaic cells.