Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
Adv Mater. 2017 Sep;29(34). doi: 10.1002/adma.201701507. Epub 2017 Jun 20.
A cross-linkable dual functional polymer hybrid electron transport layer (ETL) is developed by simply adding an amino-functionalized polymer dopant (PN4N) and a light crosslinker into a commercialized n-type semiconductor (N2200) matrix. It is found that the resulting hybrid ETL not only has a good solvent resistance, facilitating multilayers device fabrication but also exhibits much improved electron transporting/extraction properties due to the doping between PN4N and N2200. As a result, by using PTB7-Th:PC BM blend as an active layer, the inverted device based on the hybrid ETL can yield a prominent power conversion efficiency of around 10.07%. More interestingly, photovoltaic property studies of bilayer devices suggest that the absorption of the hybrid ETL contributes to photocurrent and hence the hybrid ETL simultaneously acts as both cathode interlayer material and an electron acceptor. The resulting inverted polymer solar cells function like a novel device architectures with a combination of a bulk heterojunction device and miniature bilayer devices. This work provides new insights on function of ETLs and may be open up a new direction for the design of new ETL materials and novel device architectures to further improve device performance.
通过简单地将氨基官能化聚合物掺杂剂（PN4N）和光交联剂添加到商业化的 n 型半导体（N2200）基质中，开发出一种可交联的双功能聚合物混合电子传输层（ETL）。结果表明，所得混合 ETL 不仅具有良好的耐溶剂性，有利于多层器件的制造，而且由于 PN4N 和 N2200 之间的掺杂，还表现出改善的电子传输/提取性能。因此，以 PTB7-Th:PC71BM 共混物作为活性层，基于混合 ETL 的倒置器件可产生约 10.07%的显著功率转换效率。更有趣的是，双层器件的光伏性能研究表明，混合 ETL 的吸收有助于光电流，因此混合 ETL 同时充当阴极界面材料和电子受体。所得的倒置聚合物太阳能电池的功能类似于具有体异质结器件和微型双层器件组合的新型器件结构。这项工作为 ETL 的功能提供了新的见解，并可能为设计新型 ETL 材料和新型器件结构以进一步提高器件性能开辟新的方向。
