Benzothiadiazole (BT) is an electron-deficient unit with fused aromatic core, which can be used to construct conjugated polymers for application in organic solar cells (OSCs). In the past twenty years, huge numbers of conjugated polymers based on BT unit have been developed, focusing on the backbone engineering (such as by using different copolymerized building blocks), side chain engineering (such as by using linear or branch side units), using heteroatoms (such as F, O and S atoms, and CN group), etc. These modifications enable BT-polymers to exhibit distinct absorption spectra (with onset varied from 600 nm to 1000 nm), different frontier energy levels and crystallinities. As a consequence, BT-polymers have gained much attention in recent years, and can be simultaneously used as electron donor and electron acceptor in OSCs, providing the power conversion efficiencies (PCEs) over 18% and 14% in non-fullerene and all-polymer OSCs. In this article, we provide an overview of BT-polymers for OSCs, from donor to acceptor, via selecting some typical BT-polymers in different periods. We hope that the summary in this article can invoke the interest to study the BT-polymers toward high performance OSCs, especially with thick active layers that can be potentially used in large-area devices.

苯并噻二唑（BT）是具有稠合芳族核的缺电子单元，可用于构建用于有机太阳能电池（OSC）的共轭聚合物。在过去的20年中，已经开发了大量基于BT单元的共轭聚合物，重点关注主链工程（例如通过使用不同的共聚结构单元），侧链工程（例如通过使用线性或分支侧链单元），这些修饰使BT聚合物表现出不同的吸收光谱（起始范围从600 nm到1000 nm），不同的前沿能级和结晶度。因此，近年来BT聚合物引起了广泛关注，并可以同时用作OSC中的电子给体和电子受体，在非富勒烯和全聚合物OSC中提供超过18％和14％的功率转换效率（PCE）。在本文中，我们概述了从供体到受体的用于OSC的BT聚合物，通过选择不同时期的一些典型BT聚合物。我们希望本文中的概述能够引起人们的兴趣，以研究针对高性能OSC的BT聚合物，特别是具有可能用于大面积设备的厚有源层的情况。