ORIGINAL PAPER A study of electrochemical behavior of quinazolin derivatives as novel additives and their specific effects on the performance of dye-sensitized solar cells Mohammad Mazloum-Ardakani 1 & Rezvan Arazi 1 & Fatemeh Tamaddon 1 & Mohammad Taghi Kazemi 1 Received: 26 September 2016 /Revised: 29 December 2016 /Accepted: 6 January 2017 # Springer-Verlag Berlin Heidelberg 2017 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 (J sc ) and open-circuit voltage (V oc ) 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 incre- ment in the charge transfer resistance due to the formation of a complex between the electrolyte additives and iodine, as charac- terized by an absorption peak around 350 nm in the UV–vis spectra. It resulted in a decrease in J sc of the dye-sensitized solar cells from 17.4 to 15 mA cm -2 . This adverse effect on J sc 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 V oc and η were enhanced for 25 and 17.11%, respectively, in comparison with the standard electrolyte. Keywords Dye-sensitized solar cells . Electrolyte . Additive . Quinazolin derivatives . Cyclic voltammetry Introduction Dye-sensitized solar cells (DSCs) are a type of photovoltaic cells which, owing to their high photochemical stability, are used in wide bandgap semiconductors as photoanodes for the cells. DSCs work without needing a built-in electrical field and without a drastic control of the purity of materials. Also, the presence of an immense internal interface is crucial for their good functioning. The basic structure of a DSC is a mesoporous layer of semiconductor oxide nanoparticles, which are sintered together to establish a strict electric contact between the particles. The nanoparticle film is deposited on a glass plate covered with a transparent conducting oxide (TCO) which allows light to enter the cells. There is a mono- layer of dye molecules attached to the surface of the metal oxide. These dye molecules serve to absorb and collect the light. The sensitized film is surrounded by an electrolyte so- lution of high ionic strength, usually composed of an organic solvent containing a redox pair. The most successful combi- nation of materials is still the one reported in an earlier study by the Grätzel group [1] on DSCs. In this basic structure, the main components are a layer of nanoparticles sensitized by a ruthenium complex dye with an iodide/triiodide redox couple in an organic solvent, which acts as a redox mediator. The success of the iodide/triiodide couple in DSCs can be attrib- uted to its favorable kinetics. Grätzel and O’Regan found a successful combination of a nanostructured semiconductor electrode with an efficient and stable dye. In a mesoporous semiconductor film, the incoming photons can be captured significantly although the surface is covered only with a monolayer of dye. The reason is that, for dye adsorption, a Highlights • We study on the electrochemical behavior of quinazolin derivatives as the new additives in DSCs. • The oxidation form of additive can improve open-circuit voltage and conversation efficiency of DSCs significantly. • The new additives can reduce dark current because of retarding charge recombination in DSCs. Electronic supplementary material The online version of this article (doi:10.1007/s11581-017-1980-6) contains supplementary material, which is available to authorized users. * Mohammad Mazloum-Ardakani mazloum@yazd.ac.ir 1 Department of Chemistry, Faculty of Science, Yazd University, Yazd, IR 89195-741, Iran Ionics DOI 10.1007/s11581-017-1980-6