Solar energy, as a clean and renewable source, can be introduced as a suitable alternative to fossil fuels, which converts light energy into electricity using the photovoltaic (PV) phenomenon. In general, solar cells fall into three categories; first generation, second generation, and third generation. One of the types of solar cells that was noticed in the scientific community belonged to the third generation of PV cells, known as dye-sensitized solar cells (DSSCs). Unlike silicon-based solid-state solar cells, DSSCs do not depend on the principles of p-n junctions for their operation. Today, silicon solar cells have the largest share of the economic market of solar cells, due to their high efficiency. However, there may be limitations due to the high cost of producing these solar cells. The DSSCs are a type of cheap solar cells belonging to the category of thin film solar cells. The basis of the work of these cells is a semiconductor formed by a light-sensitive anode and an electrolyte. Although the energy conversion efficiency in these cells is lower than other solar cells, what has led to the development of this generation of cells is their low price-to-performance ratio, which has made energy production significantly affordable. In this chapter, we will first introduce the types of solar cells and, then DSSCs, their structure, and performance will be discussed. The research in the field of DSSCs has progressed rapidly during the last two decades, owing to the low cost, lack of structural complexity, long-term stability, and good efficiency.
