Design and Synthesis of Organic Dyes and Their Application in New Generation Photovoltaics

Dye-Sensitized Solar Cells (DSSC) represent a very promising technology to convert solar energy in electric current, due to their low cost of production and their colorful and decorative features. The core component of a DSSC is the sensitizer. In this contest metal-free organic dyes have been successfully used, offering the advantages to enhance light harvesting by tuning the absorption over a broad spectral range and pursuing high extinction coefficents. Furthermore, expensive and hazardous metals are avoided. Our interest in the field involved the design, with the aid of DFT computational analysis, and the synthesis of new organic dyes in order to study their structure-property relationships and exploit a possible application in DSSC. Organic dyes possessing donor and acceptor moieties bridged by a ?-conjugated unit (called D-?-A structure) have been mainly investigated. Some of these dyes showed interesting features such as extremely intense light absorption in the visible spectrum, good stability and very good power conversion efficiencies, proving to be suitable for application in transparent thin-layer DSSCs.