Beijing National Research Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Adv Mater. 2019 Jan;31(2):e1804657. doi: 10.1002/adma.201804657. Epub 2018 Nov 12.
Herein, poly(vinylpyrrolidone) (PVP) is used as the cathode interlayer (CIL) through the self-organization method in inverted organic solar cells (OSCs). By coating a solution of PVP and active layer materials onto a glass/indium tin oxide (ITO) substrate, the PVP can segregate to the near ITO side due to its high surface energy and strong intermolecular interaction with the ITO electrode. The power conversion efficiency (PCE) of the obtained OSC device reaches 13.3%, much higher than that of the control device with a PCE of only 10.1%. The improvement results from the increased exciton dissociation efficiency and the depressed trap-assisted recombination, which can be attributed to the reduced work function of the cathode by the self-organized PVP. Additionally, the molecular weight of the PVP has almost no influence on the device performance, and the PVP-modified device presents superior stability. This method can also be applied in other highly efficient fullerene-free OSCs, and with a fine selection of the active layer, a high PCE of 14.0% is obtained. Overall, this work demonstrates the great potential of the PVP-based CIL in inverted OSCs fabricated via the self-organization method.
在此，聚维酮（PVP）通过自组织方法被用作倒置有机太阳能电池（OSC）的阴极界面层（CIL）。通过将 PVP 和活性层材料的溶液涂覆到玻璃/氧化铟锡（ITO）基底上，由于其高表面能和与 ITO 电极的强分子间相互作用，PVP 可以分离到靠近 ITO 的一侧。所得 OSC 器件的功率转换效率（PCE）达到 13.3%，远高于仅为 10.1%的对照器件。这种改进归因于激子解离效率的提高和陷阱辅助复合的抑制，这可以归因于自组织的 PVP 降低了阴极的功函数。此外，PVP 的分子量对器件性能几乎没有影响，且 PVP 改性器件具有优异的稳定性。这种方法也可以应用于其他高效的无富勒烯 OSC，并且通过对活性层的精细选择，可以获得 14.0%的高 PCE。总的来说，这项工作证明了基于 PVP 的 CIL 在通过自组织方法制备的倒置 OSC 中的巨大潜力。
