Synthesis of pyridine derivatives and their influence as additives on the photocurrent of dye-sensitized solar cells

Abstract

New kinds of additive, 4-alkyloxypyridne derivatives, were synthesized by introducing an alkyloxy group into the 4-position of 2-methylpyridine. The influence of these electrolyte additives on the short-circuit photocurrent (J sc) of dye sensitized solar cells was investigated by combining electrochemical and spectral techniques. With the addition of pyridine derivatives to the electrolyte, a decrease in the rate of dye regeneration was observed by laser flash photolysis measurements and cyclic voltammetry, whereas, measurement of electrochemical impedence spectra showed an increase in the charge transfer resistance due to the formation of a complex between the pyridine derivatives and iodine, as identified by an absorption peak around 378 nm in the UV–Vis spectra. This leads to a decrease in J sc of dye-sensitized solar cells. This adverse effect on the J sc can be attributed to reaction or coordination between the dye cations and the iodine in the electrolyte.