State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Adv Mater. 2023 Apr;35(16):e2210865. doi: 10.1002/adma.202210865. Epub 2023 Mar 14.
Efficient photon utilization is key to achieving high-performance organic photovoltaic (OPV) cells. In this study, a multiscale fibril network morphology in a PBQx-TCl:PBDB-TF:eC9-2Cl-based system is constructed by regulating donor and acceptor phase-transition kinetics. The distinctive phase-transition process and crystal size are systematically investigated. PBQx-TCl and eC9-2Cl form fibril structures with diameters of ≈25 nm in ternary films. Additionally, fine fibrils assembled by PBDB-TF are uniformly distributed over the fibril networks of PBQx-TCl and eC9-2Cl. The ideal multiscale fibril network morphology enables the ternary system to achieve superior charge transfer and transport processes compared to binary systems; these improvements promote enhanced photon utilization efficiency. Finally, a high power conversion efficiency of 19.51% in a single-junction OPV cell is achieved. The external quantum efficiency of the optimized ternary cell exceeds 85% over a wide range of 500-800 nm. A tandem OPV cell is also fabricated to increase solar photon absorption. The tandem cell has an excellent PCE of more than 20%. This study provides guidance for constructing an ideal multiscale fibril network morphology and improving the photon utilization efficiency of OPV cells.
提高光子利用效率是实现高性能有机光伏（OPV）电池的关键。在这项研究中，通过调节给体和受体相转变动力学，构建了基于 PBQx-TCl:PBDB-TF:eC9-2Cl 的多尺度原纤网络形态。系统研究了独特的相转变过程和晶体尺寸。在三元薄膜中，PBQx-TCl 和 eC9-2Cl 形成直径约为 25nm 的原纤结构。此外，PBDB-TF 组装的细原纤均匀分布在 PBQx-TCl 和 eC9-2Cl 的原纤网络中。理想的多尺度原纤网络形态使三元体系与二元体系相比，实现了更优异的电荷转移和输运过程，从而提高了光子利用效率。最终，在单结 OPV 电池中实现了 19.51%的高光能量转换效率。优化后的三元电池的外量子效率在 500-800nm 的宽范围内超过 85%。还制备了串联 OPV 电池以增加太阳能光子的吸收。串联电池的 PCE 超过 20%。本研究为构建理想的多尺度原纤网络形态和提高 OPV 电池的光子利用效率提供了指导。
