Comparative study of the performance of solar cells based on cochineal and Black Dye N749 with several mordant and brighteners

Abstract

Even though there is a strong tendency to develop DSSCs based on natural dyes, while these reach a sufficiently high level of development to be commercialized, cells based on inorganic synthetic dyes, such as Ruthenium, will continue to be analyzed and improved. These improvements include new dyes, such as Black Dye N749 (BD), one of the most used synthetic dyes. A comparative analysis of the current output profiles of cells based on cochineal and black dye is reported. It was observed that BD has to be catalyzed to produce a high output current: by itself, this dye showed low output currents, but when it is catalyzed, its performance significantly improves. Cochineal shows, when used alone, a high output current. Different additives were tested: Alum and Sn as a mordant and mineral carbon as a catalyst, which contains ions of Fe²⁺ and Fe³⁺; these significantly modify the shape (rising or decreasing) and intensity of the output current profiles. Unstable oscillations appear in the current profile when the cell is abruptly illuminated; a model was included to fit the experimental data.