Alternative Sources of Natural Photosensitizers: Role of Algae in Dye-Sensitized Solar Cell

Abstract

In this paper, the potential of marine algae to act as sensitizers is systematically studied and presented. We aim to find a feasible financial strategy to enhance the global efficiency of dye-sensitized solar cells (DSSC). Algae are mainly composed of chlorophylls, carotenoids, flavonoids, and Betalains, which are essential pigments that confer unique characteristics that are required in natural sensitizers. Therefore, this review aims to unveil and understand the underlying mechanism between algae pigments and photoelectrodes and to conduct a comprehensive analysis to determine the effect of algae dye on light absorption efficiency and electron transport. The structural, morphological, optical, and electrochemical impedance properties are deeply analyzed, and we show the current opportunities for natural dyes to be used in energy technologies through DSSC. A comparison of several bibliographic sources dealing with DSSC based on algae provided a general overview of the improvements in factors such as the recombination times, the filling factor, and the Voc values. The contributions of this paper relate to the conversion efficiency and future applications in the DSSC field. Finally, this review exemplifies that the nature of the pigment affects the photophysical properties of the cell. Thus, this paper may contribute to future investigations of DSSC when choosing efficient natural dyes according to their optical and electronic properties. Therefore, this work provides the knowledge required to efficiently merge materials and dyes, in which photovoltaic energy systems’ reproducibility and scalability still represent a challenge. Lastly, this document discusses the natural pigments’ stability and the approaches to improve their chemical stability.