Organic solar cells (OSCs) have attracted considerable interests from both academic and industrial community over the past decade due to the potentials such as low cost

tunable flexibility and high specific weight. The design of novel organic donors and optimization of device structures have helped to boost the power conversion efficiency to over 10 %. From the aspect of the material design

a wide variety of donor and acceptor units were developed to build the organic conjugated donors. Among which

benzothiadiazole (BT) unit is widely used in constructing high-efficiency OSCs materials due to its large conjugate plane and strong electron-withdrawing properties. In this review

we present an overview the recent progress of the BT-based organic photovoltaic materials and their application in OSCs.