Experimental evidence that short-range intermolecular aggregation is sufficient for efficient charge transport in conjugated polymers
2015 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 112, no 34, 10599-10604 p.Article in journal (Refereed) Published
Efficiency, current throughput, and speed of electronic devices are to a great extent dictated by charge carrier mobility. The classic approach to impart high carrier mobility to polymeric semiconductors has often relied on the assumption that extensive order and crystallinity are needed. Recently, however, this assumption has been challenged, because high mobility has been reported for semiconducting polymers that exhibit a surprisingly low degree of order. Here, we show that semiconducting polymers can be confined into weakly ordered fibers within an inert polymer matrix without affecting their charge transport properties. In these conditions, the semiconducting polymer chains are inhibited from attaining long-range order in the p-stacking or alkyl-stacking directions, as demonstrated from the absence of significant X-ray diffraction intensity corresponding to these crystallographic directions, yet still remain extended along the backbone direction and aggregate on a local length scale. As a result, the polymer films maintain high mobility even at very low concentrations. Our findings provide a simple picture that clarifies the role of local order and connectivity of domains.
Place, publisher, year, edition, pages
National Academy of Sciences , 2015. Vol. 112, no 34, 10599-10604 p.
organic electronics; conjugated polymers; aggregation; charge transport
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:liu:diva-121306DOI: 10.1073/pnas.1501381112ISI: 000360005600036PubMedID: 26261305OAI: oai:DiVA.org:liu-121306DiVA: diva2:854296
Funding Agencies|Advanced Functional Materials Center at Linkoping University; Onnesjo Foundation; Knut and Alice Wallenberg Foundation; Swedish Foundation for Strategic Research; Swedish Governmental Agency for Innovation Systems (VINNOVA); National Science Foundation [DMR 1205752]; US Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]2015-09-162015-09-142015-09-30