A study of electrochemical behavior of quinazolin derivatives as novel additives and their specific effects on the performance of dye-sensitized solar cells

Abstract

As a new kind of additives, quinazolin derivatives were synthesized in oxidation and reduction forms. The influence of these electrolyte additives on the short-circuit photocurrent (Jsc) and open-circuit voltage (Voc) of dye-sensitized solar cells was investigated by electrochemical and impedance techniques. After addition of quinazolin derivatives to an electrolyte, cyclic voltammetry revealed a decrease in the rate of dye regeneration whereas electrochemical impedance spectra showed an increment in the charge transfer resistance due to the formation of a complex between the electrolyte additives and iodine, as characterized by an absorption peak around 350 nm in the UV–vis spectra. It resulted in a decrease in Jsc of the dye-sensitized solar cells from 17.4 to 15 mA cm−2. This adverse effect on Jsc can be attributed to the reaction or the coordination between the dye cations and the iodine in the electrolyte. In spite of the decrease in the short-circuit photocurrent, the open-circuit voltage and the conversation efficiency (η) increased significantly. The Voc and η were enhanced for 25 and 17.11%, respectively, in comparison with the standard electrolyte.