Benzothiadiazoles are heterocyclic compounds in which a benzene ring is fused to a thiadiazole ring. They have strong electron-accepting ability and high thermal stability. Benzothiadiazoles and their analogs can form stable free radicals, making them useful in semiconductor materials. In small-molecule semiconductors, they are often used to improve electron mobility and reduce recombination losses. Their versatile chemistry allows the synthesis of a wide range of derivatives with tailored properties.