High Performance All-Polymer Solar Cells by Synergistic Effects of Fine-Tuned Crystallinity and Solvent Annealing
2016 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 138, no 34, 10935-10944 p.Article in journal (Refereed) Published
Growing interests have been devoted to the design of polymer acceptors as potential replacement for fullerene derivatives for high-performance all polymer solar cells (all-PSCs). One key factor that is limiting the efficiency of all-PSCs is the low fill factor (FF) (normally amp;lt;0.65), which is strongly correlated with the mobility and film morphology of polymer:polymer blends. In this work, we find a facile method to modulate the crystallinity of the well-known naphthalene diimide (NDI) based polymer N2200, by replacing a certain amount of bithiophene (2T) units in the N2200 backbone by single thiophene (T) units and synthesizing a series of random polymers PNDI-Tx, where x is the percentage of the single T. The acceptor PNDI-T10 is properly miscible with the low band gap donor polymer PTB7-Th, and the nanostructured blend promotes efficient exciton dissociation and charge transport. Solvent annealing (SA) enables higher hole and electron mobilities, and further suppresses the bimolecular recombination. As expected, the PTB7-Th:PNDI-T10 solar cells attain a high PCE of 7.6%, which is a 2-fold increase compared to that of PTB7-Th:N2200 solar cells. The FF of 0.71 reaches the highest value among all-PSCs to date. Our work demonstrates a rational design for fine-tuned crystallinity of polymer acceptors, and reveals the high potential of all-PSCs through structure and morphology engineering of semicrystalline polymer:polymer blends.
Place, publisher, year, edition, pages
AMER CHEMICAL SOC , 2016. Vol. 138, no 34, 10935-10944 p.
IdentifiersURN: urn:nbn:se:liu:diva-131683DOI: 10.1021/jacs.6b04822ISI: 000382513300043PubMedID: 27479751OAI: oai:DiVA.org:liu-131683DiVA: diva2:1014869
Funding Agencies|OSNIRO ; Swedish Research Council; Swedish Research Council Formas; Swedish Energy Agency; EU projects SUNFLOWER-"Sustainable Novel Flexible Organic Watts Efficiently Reliable" ; Chalmers Area of Advance Materials Science and Energy; Knut and Alice Wallenberg foundation; program for the Excellent Doctoral Dissertations of Guangdong Province [ybzzxm201114]; National Natural Science Foundation of China [21504066, 21534003]; Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy [DE-AC02-05CH11231]; European Research Council under the European Union ; Ministry of Education, Culture, and Science (NWO) [024.001.035]2016-10-032016-09-302016-10-03