Hole-transporting poly(dendrimer)s as electron donors for low donor organic solar cells with efficient charge transport
- Recent work on bulk-heterojunction organic solar cells has shown that photoexcitation of the electron acceptor followed by photoinduced hole transfer can play a significant role in photocurrent generation. To establish a clear understanding of the role of the donor in the photoinduced hole transfer process, we have synthesized a series of triphenylamine-based hole-transporting poly(dendrimer)s with mechanically flexible nonconjugated backbones via ring-opening metathesis polymerization and used them in low donor content solar cells. The poly(dendrimer)s were found to retain the hole transporting properties of the parent dendrimer, with hole mobilities of similar to 10(-3) cm(2)/(V s) for solution processed neat films. However, when blended with [6,6]-phenyl-C-70-butyric acid methyl ester (PC70BM), the best performing poly(dendrimer) was found to form films that had balanced and relatively high hole/electron mobilities of similar to 5 x 10(-4) cm(2) /(V s). In contrast, at the same concentration the parent dendrimer:PC70BM blend wasRecent work on bulk-heterojunction organic solar cells has shown that photoexcitation of the electron acceptor followed by photoinduced hole transfer can play a significant role in photocurrent generation. To establish a clear understanding of the role of the donor in the photoinduced hole transfer process, we have synthesized a series of triphenylamine-based hole-transporting poly(dendrimer)s with mechanically flexible nonconjugated backbones via ring-opening metathesis polymerization and used them in low donor content solar cells. The poly(dendrimer)s were found to retain the hole transporting properties of the parent dendrimer, with hole mobilities of similar to 10(-3) cm(2)/(V s) for solution processed neat films. However, when blended with [6,6]-phenyl-C-70-butyric acid methyl ester (PC70BM), the best performing poly(dendrimer) was found to form films that had balanced and relatively high hole/electron mobilities of similar to 5 x 10(-4) cm(2) /(V s). In contrast, at the same concentration the parent dendrimer:PC70BM blend was found to have a hole mobility of 4 orders of magnitude less than the electron mobility. The balanced hole and electron mobilities for the 6 wt % poly(dendrimer):PC70BM blend led to an absence of second-order bimolecular recombination losses at the maximum power point and resulted in a fill factor of 0.65 and a PCE 2.1% for the devices, which was almost three times higher than the cells composed of the parent dendrimer:PC70BM blends.…
Author details: | Wei JiangORCiD, Martin StolterfohtORCiD, Hui Jin, Paul L. BurnORCiD |
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DOI: | https://doi.org/10.1021/acs.macromol.0c00520 |
ISSN: | 0024-9297 |
ISSN: | 1520-5835 |
Title of parent work (English): | Macromolecules : a publication of the American Chemical Society |
Publisher: | American Chemical Society |
Place of publishing: | Washington |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/04/17 |
Publication year: | 2020 |
Release date: | 2023/04/21 |
Volume: | 53 |
Issue: | 8 |
Number of pages: | 10 |
First page: | 2902 |
Last Page: | 2911 |
Funding institution: | University of Queensland (Strategic Initiative-Centre for Organic; Photonics Electronics)University of Queensland; Australian Government; through the Australian Renewable Energy Agency (ARENA) Australian Centre; for Advanced Photovoltaics (ACAP)Australian Renewable Energy Agency; (ARENA) |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |