초록 |
Over the past few decades, polymer solar cells (PSCs) have made a significant progress, showing their potential in low-cost, flexible, lightweight, portable and large-area energy-harvesting devices. We present a series of crystalline low bandgap polymers which were designed by considering the backbone planarity, noncovalent intra- and interchain interactions and solution processibility, leading to highly ordered film morphologies, deep highest occupied molecular orbital (HOMO) level, balanced electron and hole mobilities. The molecular design and resulting morphological, electrical and device properties will be discussed in detail. Devices based on these polymers exhibit outstanding long-term thermal stability at 130 oC for over 200 h and the highest PCE over 9% in a conventional PSC having a single-cell device structure with a ~300 nm thick active layer. |