The technology of polymer-based organic photovoltaic (OPV) cells has made great progress in the past decade, with the power conversion efficiency increasing from just a few per cent to around 12%, and the stability increasing from hours to years. One of the important milestones in this progress has been the invention of infrared-absorbing low-bandgap polymers, which allows the OPV cells to form effective tandem structures for harvesting near-infrared energy from the solar spectrum. In this Review, we focus on the progress in low-bandgap conjugated polymers and several tandem OPV cells enabled by these low-bandgap polymers. Specifically, we cover polymer-based tandem solar cells; hybrid tandem solar cells combining polymers with hydrogenated amorphous silicon; and unconventional solar cells. For each of these technologies, we address the challenges and offer our perspectives for future development.

在过去的十年中，基于聚合物的有机光伏（OPV）电池技术取得了长足的进步，功率转换效率从仅百分之几提高到了约12％，稳定性从数小时增长到了几年。该进展的重要里程碑之一是发明了吸收红外的低带隙聚合物，该聚合物使OPV电池能够形成有效的串联结构，以从太阳光谱中收集近红外能量。在本综述中，我们重点介绍低带隙共轭聚合物和由这些低带隙聚合物实现的几个串联式OPV电池的研究进展。具体来说，我们涵盖了基于聚合物的串联太阳能电池；混合串联太阳能电池，结合了聚合物和氢化非晶硅；和非常规的太阳能电池。对于每种技术，