title: Singlet exciton fission in nanostructured organic solar cells.
abstract: Singlet exciton fission is an efficient multiexciton generation process in organic molecules. But two concerns must be satisfied before it can be exploited in low-cost solution-processed organic solar cells. Fission must be combined with longer wavelength absorption in a structure that can potentially surpass the single junction limit, and its efficiency must be demonstrated in nanoscale domains within blended devices. Here, we report organic solar cells comprised of tetracene, copper phthalocyanine, and the buckyball C(60). Short wavelength light generates singlet excitons in tetracene. These are subsequently split into two triplet excitons and transported through the phthalocyanine. In addition, the phthalocyanine absorbs photons below the singlet exciton energy of tetracene. To test tetracene in nanostructured blends, we fabricate coevaporated bulk heterojunctions and multilayer heterojunctions of tetracene and C(60). We measure a singlet fission efficiency of (71 ± 18)%, demonstrating that exciton fission can efficiently compete with exciton dissociation on the nanoscale.
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States. pjadhav@mit.edu
authors.forename: Priya J
authors.initials: PJ
authors.lastname: Jadhav
authors.forename: Aseema
authors.initials: A
authors.lastname: Mohanty
authors.forename: Jason
authors.initials: J
authors.lastname: Sussman
authors.forename: Jiye
authors.initials: J
authors.lastname: Lee
authors.forename: Marc A
authors.initials: MA
authors.lastname: Baldo
mesh_terms: D011211:Electric Power Supplies; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D009930:Organic Chemicals / Q000737:chemistry*; D012542:Scattering, Radiation; D012993:Solar Energy
chemical_list: D009930:Organic Chemicals