Application of polyoxometalates in third-generation solar cells

Researchers pursuing the development of third-generation solar cells, which typically include quantum dot-sensitized solar cells (QDSSCs), dye-sensitized solar cells (DSSCs), perovskite solar cells (PSCs), and organic solar cells (OSCs), continue to prioritize low cost, simple preparation, high efficiency, and stability. Polyoxometalates (POMs) are a class of inorganic anionic metallic oxygen cluster compounds with abundant charge, skeleton structure, and excellent physical and chemical properties, such as strong electron acceptability, adjustable energy band structure, and reversible multi-electron redox properties. They are also inexpensive and environmentally friendly. Owing to these exceptional characteristics, POMs are used as building blocks for synthesizing other nanomaterials. Notably, leveraging the extraordinary characteristics of POMs to reduce costs and improve the efficiency and stability of solar cells is an effective strategy for addressing the current energy crisis. In this review, we summarize the research progress of various POM molecules and their derived POM-based nanomaterials in enhancing the performance of third-generation solar cells. Promising development prospects of POMs in the field of photovoltaic devices are also highlighted.