An Overview of Metal Complexes, Metal-Free and Natural Photosensitizers in Dye-Sensitized Solar Cells

Sharad A. Mahadik1

Habib M. Pathan2

Sunita Salunke-Gawali1,Email

1Department of Chemistry, Savitribai Phule Pune University, Pune 411007, India.
2Advanced Physics Laboratory, Department of Physics, Savitribai Phule Pune University, Pune 411007, India.


A lot of interest has been shown in dye-sensitized solar cells (DSSCs) as possible options for converting renewable energy sources. This review explores the latest developments in DSSCs, emphasizing the wide variety of photosensitizers used. Metal complexes, metal-free, novel naphthoquinone photosensitizers, and natural photosensitizers are all covered in the discussion; each has unique qualities and benefits that help to increase the effectiveness of DSSCs. In DSSCs, metal complexes are essential for bettering charge separation and light absorption. The complicated coordination chemistry of metal complexes allows for customized control of their optical and electrical characteristics, which enhances their performance in solar cells. Ruthenium-based photosensitizers have demonstrated high stability, efficient absorption of natural visible sunlight, and excellent redox properties. In contrast, organic and metal-free photosensitizers have become more popular because they are less expensive and better for the environment. The search for metal-free substitutes creates opportunities to develop scalable and sustainable solar cell technology. Natural photosensitizers offer a renewable and environmentally friendly approach to DSSC technology due to their exceptional light-harvesting properties and biocompatibility. The photosensitizer, electrolyte, counter electrode, and photoanode interact intricately in the DSSC mechanism. This review provides the working principles of DSSCs, focusing on recent advancements and challenges in research and development. The electrolyte, counter electrode, conductive transparent substrates such as Fluorine-doped tin oxide (SnO2: F, FTO) and indium-tin-oxide (In2O3: Sn, ITO), metal oxide semiconducting films have been included in his review. Thus, herein, we discussed the components of DSSCs, their advantages and disadvantages. The comprehensive review seeks to offer a complete picture of the condition of DSSCs today, emphasizing the advancements made in using various photosensitizers and clarifying the complex mechanisms guiding their functioning. This article's insights support continued attempts to create sustainable and effective solar energy conversion technology.

An Overview of Metal Complexes, Metal-Free and Natural Photosensitizers in Dye-Sensitized Solar Cells