Novel conjugated organic dyes for dye-sensitized solar cells

Dye-sensitized solar cells have been an intensively investigated renewable energy technology with low cost and high light-to-electrical conversion efficiency. Since their initial report in 1991 by O'Regan and Grätzel they have attracted much attention to researchers resulting into different Ru complex photosensitizers such N3, and Black dyes exhibit efficiencies higher than 10%. However, Ru is a rare metal at high cost which makes Ru dyes very expensive. Therefore, great efforts have been made toward replacing Ru based dyes with novel organic dyes. Recently different organic dyes architectured with coumarins, indolines, cyanoacrylic acids, merocynaines, polyenes and tetrahydroquinolines showed good performance. Most of them contain a donor and an acceptor bridged by p-conjugation. In this communication we report the synthesis of several new dyes that contain a diphenylamine donor and isatin with 2-cynoacrylic acid as the acceptor bridged by one or two thiophenes. Evaluation of their photophysical and electrochemical properties are currently underway and will be reported in the meeting.