Preparation and Characterization of a Dye Sensitized Solar Cell used Liquid Electrolyte

Abstract

Dye-Sensitized Solar Cell (DSSC) is a third-generation solar cell, consisting of a semiconductor electrode, a sensitizer, an electrolyte, and a counter electrode. This work aims to verify the use of various plant extracts as a natural dye inducer to improve the performance efficiency of DSSCs associated with the interaction between the dye and the TiO2 surface. Natural dyes have become more popular as an alternative to expensive and rare organic catalysts due to their low cost, non-toxicity, high performance, abundant supply of raw materials, various colours, and eco-friendly nature. In this work six natural dyes were used as photosensitizers for DSSCs which were extracted from raspberries, blackberries, spinach, red cabbage, blood orange, and beetroot. Subsequently, its optical properties were studied. During preparation of the cells, we used two types of titanium dioxide: the commercial TiO2 and laboratory–prepared meso-TiO2 as photoelectrode and the platinum as counter electrode. In this research, two different types of natural dye solar cells were adopted based on blackberry dye and another dye which is a mixture of natural dyes consisting of red cabbage + spinach + blackberry. Additionally, the photoelectrode was prepared by Electrophoretic Deposition (EPD) method that used to deposit the TiO2 layer on the FTO glass, and the counter electrode was prepared from Chloroplatinic Acid through thin layers of platinum which were deposited on the glass slides using the spin–coating method. Also, we studied the optical and structural properties of titanium dioxide powder. After several experiments, three cells were prepared (two with meso-TiO2 and one with Commercial TiO2). We collected the cells by using a liquid electrolyte, i.e., an iodine solution and tested them under illumination and in the dark then studied their electrical properties and obtained their characteristic curves. In the cell of meso- TiO2 with mix dye we got the highest value and curve of current density compared to the other cell, which is about 2.93 mA/cm2 with values of VOC = 0.76V (the open circuit voltage), FF = 62.98% (the fill factor) and the power conversion efficiency η = 1.4%. The other highest value of the power conversion efficiency was also in meso-TiO2 photoelectrode cell with blackberry dye; it equals η = 0.72 with values VOC = 0.64V, Jsc =2.29 mA/cm2, FF = 49.1%. It is hoped that this work will contribute to the exploitation of sunlight and the development of greener energy generation.