Metal-free and natural dye-sensitized solar cells: recent advancements and future perspectives

Currently, the predominant energy source utilized by humanity is fossil fuels. However, as demand surges and supplies wane, identifying alternative sources of energy becomes increasingly critical. Presently, solar energy has emerged as a promising solution to this energy crisis, and dye-sensitized solar cells (DSSCs) represent a particularly viable technology. DSSCs are the most suitable choice as a cost-effective and reliable substitute for other types of photovoltaic devices, including organic, inorganic and hybrid solar cells. This is because DSSCs can directly convert light energy into electrical energy, are simple to manufacture, require less energy to produce, and can be fabricated using abundant and non-toxic materials. In addition, they can function effectively even in environments with low lighting conditions, making them a versatile option for various applications. This review aims to provide an in-depth understanding of the operating principle, components, and progress on DSSCs. Initially, we explain the operational mechanics of DSSCs. Specifically, the process by which these cells convert solar energy into electrical energy via a photoelectrochemical mechanism is highlighted. Subsequently, we delve into the various components of DSSCs, including the photoanode, counter electrode, and electrolyte, and their respective roles in the conversion process. Furthermore, we investigate the recent advancements in DSSC technology, which encompass novel approaches such as the utilization of new materials to enhance light harvesting efficiency and the development of efficient DSSCs. Additionally, we discuss the present state of development of DSSCs, including their commercial availability and widespread adoption. Finally, we highlight the potential future prospects of DSSCs, such as their integration with other renewable energy sources and their use in building integrated photovoltaics. By gaining a comprehensive understanding of the benefits and limitations of DSSCs, we can make informed decisions on how to optimally harness this technology to meet our energy requirements sustainably and efficiently. This review aims to provide an in-depth understanding of the operating principle, components, and progress on metal free and natural dye synthesized solar cells. It also highlights the mechanism and light harvesting efficiency.