Non-fullerene acceptors are a class of organic molecules that are used in organic photovoltaic devices as an alternative to fullerene derivatives. These acceptors typically have a low molecular weight and are designed to have strong light absorption and efficient charge transport properties. Non-fullerene acceptors have gained significant attention in recent years due to their potential to improve the efficiency and stability of organic solar cells. Research in this area focuses on developing new non-fullerene acceptor materials with improved performance, understanding the underlying mechanisms of charge separation and transport in these materials, and optimizing device architecture to enhance overall solar cell efficiency.