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.
Molecular Materials and Nanosystems, Institute for Complex Molecular Systems , Eindhoven University of Technology , P.O. Box 513, Eindhoven 5600 MB , The Netherlands.
ACS Appl Mater Interfaces. 2019 Mar 20;11(11):10794-10800. doi: 10.1021/acsami.9b00337. Epub 2019 Mar 6.
Developing effective methods to make efficient bulk-heterojunction polymer solar cells at roll-to-roll relevant active layer thickness is of significant importance. We investigate the effect of fullerene content in polymer:fullerene blends on the fill factor (FF) and on the performance of thick-film solar cells for four different donor polymers PTB7-Th, PDPP-TPT, BDT-FBT-2T, and poly[5,5'-bis(2-butyloctyl)-(2,2'-bithiophene)-4,4'-dicarboxylate- alt-5,5'-2,2'-bithiophene] (PDCBT). At a few hundreds of nanometers thickness, increased FFs are observed in all cases and improved overall device performances are obtained except for PDCBT upon increasing fullerene content in blend films. This fullerene content effect was studied in more detail by electrical and morphological characterization. The results suggest enhanced electron mobility and suppressed bimolecular recombination upon increasing fullerene content in thick polymer:fullerene blend films, which are the result of larger fullerene aggregates and improved interconnectivity of the fullerene phases that provide continuous percolating pathways for electron transport in thick films. These findings are important because an effective and straightforward method that enables fabricating efficient thick-film polymer solar cells is desirable for large-scale manufacturing via roll-to-roll processing and for multijunction devices.
开发有效的方法，在卷对卷相关的活性层厚度下制备高效的体异质结聚合物太阳能电池具有重要意义。我们研究了富勒烯含量对聚合物：富勒烯共混物的填充因子（FF）和四种不同给体聚合物 PTB7-Th、PDPP-TPT、BDT-FBT-2T 和聚[5,5'-双（2-丁基辛基）-（2,2'-联噻吩）-4,4'-二羧酸酯- alt-5,5'-2,2'-联噻吩]（PDCBT）厚膜太阳能电池性能的影响。在几百纳米的厚度下，所有情况下 FF 都有所提高，除了 PDCBT 之外，整体器件性能也得到了提高，这是由于共混膜中富勒烯含量的增加。通过电学和形态学表征对富勒烯含量效应进行了更详细的研究。结果表明，在厚聚合物：富勒烯共混膜中增加富勒烯含量会提高电子迁移率并抑制双分子复合，这是由于富勒烯聚集体增大和富勒烯相的互连性提高，从而在厚膜中提供了连续的电子输运渗流途径。这些发现很重要，因为需要一种有效且简单的方法来制造高效的厚膜聚合物太阳能电池，以便通过卷对卷加工进行大规模制造，并用于多结器件。
