An unusual thiazolo[5,4-d]thiazole sensitizer for dye-sensitized solar cells

A novel unsymmetrical thiazolo[5,4-d]thiazole, TZ1, endowed with an unusual p–D–A structure featuring a highly conjugated light-harvesting backbone, has been synthesized and characterized from the photoand electrochemical point of view. Although its structure did not resemble that of typical organic sensitizers, the new compound showed properties compatible with its employment in dye-sensitized solar cells. The experimental findings were supported by the results of DFT calculations. Indeed, when tested as a sensitizer in dye-sensitized solar cells, compound TZ1 gave rise to a high average open-circuit voltage (Voc) of 0.712 V and an average short-circuit current (Jsc) of 7.0 mA cm2, resulting in a power conversion efficiency (g) of 2.55%.