Simulation analysis of Ruthenium-based Dye Sensitized Solar Cells

Abstract

Dye Sensitized Solar Cell (DSSC), usually referred as one of the most promising third generation photovoltaic devices, is an electrochemical device in which a molecule (i.e., the dye) chemisorbed onto the surface of a porous material absorbs the incident light and, thus, transfers an electron to the wide band gap semiconductor material. The injected electrons can diffuse through the semiconductor up to the collecting anode without the risk of recombination. The roles of the electrolyte which permeates the cell are to regenerate the ionized molecule and to implement a hole-transporting layer, allowing to repeat the abovementioned process. Thanks to this behaviour, semiconductors with large amounts of defects can be used with relatively good efficiency values. In a previous work, we have described the electro-optical characterization of DSSCs which use N719 ruthenium complex as the sensitizer dye, TiO2 as the wide band semiconductor material, triiodide/iodide as the electrolyte redox couple and platinum counter electrodes. Here we show our experimental results and the use of a solar cell model including all the different parts of the devices. In this way, we are able to explain the performance increase of our cells – in terms of Voc, Jsc and efficiency – with light soaking.