A New Tetracyclic Lactam Building Block for Thick, Broad-Bandgap Photovoltaics
2014 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, no 33, 11578-11581 p.Article in journal (Refereed) Published
A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on pi-stacking of the polymer backbone, which was retained in PTNT:firllerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 596 for greater than200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of greater than4% could be retained when thick active layers of similar to 400 rim were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.
Place, publisher, year, edition, pages
American Chemical Society , 2014. Vol. 136, no 33, 11578-11581 p.
IdentifiersURN: urn:nbn:se:liu:diva-110700DOI: 10.1021/ja5051692ISI: 000340737900005PubMedID: 25056482OAI: oai:DiVA.org:liu-110700DiVA: diva2:749239
Funding Agencies|Chalmers Areas of Advance Materials Science, Energy and Nanoscience and Nanotechnology; Swedish Research Council; Formas; Swedish Energy Agency; Linnaeus Centre for Bioinspired Supramolecular Function and Design; National Science Foundation; U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]2014-09-232014-09-192015-03-06