MIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Open Access Articles
  • MIT Open Access Articles
  • View Item
  • DSpace@MIT Home
  • MIT Open Access Articles
  • MIT Open Access Articles
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Improving the Performance of P3HT-Fullerene Solar Cells with Side-Chain-Functionalized Poly(thiophene) Additives: A New Paradigm for Polymer Design

Author(s)
Lobez, Jose M.; Andrew, Trisha Lionel; Bulovic, Vladimir; Swager, Timothy Manning
Thumbnail
Downloads1-ln10919681576237097-1939656818Hwf-1685227245IdV-2103471511091968PDF_HI0001.pdf (3.626Mb)
PUBLISHER_POLICY

Publisher Policy

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.

Terms of use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Metadata
Show full item record
Abstract
The motivation of this study is to determine if small amounts of designer additives placed at the polymer–fullerene interface in bulk heterojunction (BHJ) solar cells can influence their performance. A series of AB-alternating side-chain-functionalized poly(thiophene) analogues, P1–6, are designed to selectively localize at the interface between regioregular poly(3-hexylthiophene) (rr-P3HT) and PCnBM (n = 61, 71). The side chains of every other repeat unit in P1–6 contain various terminal aromatic moieties. BHJ solar cells containing ternary mixtures of rr-P3HT, PCnBM, and varying weight ratios of additives P1–6 are fabricated and studied. At low loadings, the presence of P1–6 consistently increases the short circuit current and decreases the series resistance of the corresponding devices, leading to an increase in power conversion efficiency (PCE) compared to reference P3HT/PC61BM cells. Higher additive loadings (>5 wt %) lead to detrimental nanoscale phase separation within the active layer blend and produce solar cells with high series resistances and low overall PCEs. Small-perturbation transient open circuit voltage decay measurements reveal that, at 0.25 wt % incorporation, additives P1–6 increase charge carrier lifetimes in P3HT/PC61BM solar cells. Pentafluorophenoxy-containing polymer P6 is the most effective side-chain-functionalized additive and yields a 28% increase in PCE when incorporated into a 75 nm thick rr-P3HT/PC61BM BHJ at a 0.25 wt % loading. Moreover, devices with 220 nm thick BHJs containing 0.25 wt % P6 display PCE values of up to 5.3% (30% PCE increase over a control device lacking P6). We propose that additives P1–6 selectively localize at the interface between rr-P3HT and PCnBM phases and that aromatic moieties at side-chain termini introduce a dipole at the polymer–fullerene interface, which decreases the rate of bimolecular recombination and, therefore, improves charge collection across the active layer.
Date issued
2012-02
URI
http://hdl.handle.net/1721.1/74240
Department
Massachusetts Institute of Technology. Department of Chemistry; Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science; Massachusetts Institute of Technology. Microsystems Technology Laboratories
Journal
ACS Nano
Publisher
American Chemical Society
Citation
Lobez, Jose M. et al. “Improving the Performance of P3HT–Fullerene Solar Cells with Side-Chain-Functionalized Poly(thiophene) Additives: A New Paradigm for Polymer Design.” ACS Nano 6.4 (2012): 3044–3056. Web.
Version: Author's final manuscript
ISSN
1936-0851
1936-086X

Collections
  • MIT Open Access Articles

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries
PrivacyPermissionsAccessibilityContact us
MIT
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.