The applications of phthalocyanine-based photosensors in dye-sensitive solar cells

Phthalocyanines are aromatic macrocyclic compounds containing 8 nitrogen and 8 carbon atoms, forming an 18-π electron system derived from 4 isoindole units. The delocalization of π electrons in the ring enhances the light absorption capacity of the molecules. The structure's high thermal stability is attributed to the surrounding nitrogen atoms. Phthalocyanines have found diverse applications due to their chemical stability and absorption capacity in the appropriate wavelength range (600-800 nm). They are particularly favored in photovoltaic applications. However, strong π-π interactions between molecules can lead to aggregation, thereby affecting the efficiency of solar cells. Therefore, the optimization of parameters such as light absorption capacity and aggregation is crucial to prevent aggregation and enhance the efficiency of phthalocyanines in solar cells. In this master's thesis, various phthalocyanine derivatives with different functional groups, serving as photosensitizers, were synthesized to replace the carboxylic acid (COOH) binding group in the molecular structure with an imidazole group. The electrochemical and photophysical properties of these derivatives were characterized and compared. Additionally, the synthesized derivatives were employed as photosensitizers in dye-sensitized solar cells, and their photovoltaic performances were evaluated. Different phthalocyanine derivatives containing the imidazole group were synthesized in this study as alternatives to the carboxylic acid (COOH) binding group. The electrochemical and photophysical properties of these derivatives were investigated and compared. These characterization studies were conducted to gain insights into the electronic and optical properties of the molecules. Furthermore, the synthesized phthalocyanine derivatives were utilized as photosensitizers in dye-sensitized solar cells, and their photovoltaic performances were examined. These investigations are important for better understanding the applications of phthalocyanines in solar cells and for improving their efficiency.