Polymer donors refer to the materials used in organic photovoltaic devices as the donor component. Organic photovoltaic devices are a type of solar cell that convert sunlight into electricity by utilizing organic materials as the active components. Polymer donors are typically conjugated polymers that can transport charges efficiently and have good light-absorbing properties. These materials are often used in combination with fullerene acceptors or other electron acceptors in organic photovoltaic devices to create a donor-acceptor system that can efficiently separate and transport charges to generate electricity. Polymer donors have attracted significant attention in recent years for their potential to provide a low-cost and flexible alternative to traditional silicon-based solar cells. Research in this area focuses on developing new polymer materials with improved efficiency, stability, and scalability for commercial applications.