Nitrogen Functionalized Perylene Materials as Cathode Interlayers in Organic Photovoltaics

The application of organic materials as cathode interlayers (CILs) in organic photovoltaics (OPVs) is an emerging strategy to increase their performance. Polar groups on CILs serve to tune the work function of the cathode as well to block holes from the donor materials in the bulk heterojunction, allowing for efficient charge cascade and thus increased performance. CILs such as PFN-Br and PDINN are known high performance CILs used in conventional OPVs, both of which are processable from green solvents which do not affect the underlying bulk heterojunction upon printing/casting, which is critical to the performance of the devices.[1,2] In terms of PDINN and CILs of the like, these compounds utilize amines appended at the imide positions that are capable of doping the perylene π-conjugated core via intramolecular electron transfer independent of conjugation. In this work, nitrogen functionalization on the core of perylene materials, such as perylene diimides and perylene tetraesters, is explored. These materials were applied as CILs to provide high performance & green solvent processable OPVs, and serve to fill the gap in the knowledge in terms of nitrogen doped perylene CILs via core functionalization.<br/><br/><u>References</u><br/>1. Fu, J.; Fong, P. W. K.; Liu, H.; Huang, C.-S.; Lu, X.; Lu, S.; Abdelsamie, M.; Kodalle, T.; Sutter-Fella, C. M.; Yang, Y.; Li, G. <i>Nat. Commun.</i> <b>2023</b>, <i>14</i>, 1760. https://doi.org/10.1038/s41467-023-37526-5.<br/>2. Yao, J.; Qiu, B.; Zhang, Z.-G.; Xue, L.; Wang, R.; Zhang, C.; Chen, S.; Zhou, Q.; Sun, C.; Yang, C.; Xiao, M.; Meng, L.; Li, Y. <i>Nat. Commun.</i> <b>2020</b>, <i>11</i>, 2726. https://doi.org/10.1038/s41467-020-16509-w.