Singlet Fission in Thin Solid Films of Bis(thienyl)diketopyrrolopyrroles

David Rais; Petr Toman; Jiří Pfleger; Udit Acharya; Yadu R Panthi; Miroslav Menšík; Alexander Zhigunov; Muhammed A Thottappali; Martin Vala; Aneta Marková; Stanislav Stříteský; Martin Weiter; Martin Cigánek; Jozef Krajčovič; Karel Pauk; Aleš Imramovský; Alexandr Zaykov; Josef Michl

doi:10.1002/cplu.202000623

Singlet Fission in Thin Solid Films of Bis(thienyl)diketopyrrolopyrroles

Chempluschem. 2020 Dec;85(12):2689-2703. doi: 10.1002/cplu.202000623.

Authors

David Rais¹, Petr Toman¹, Jiří Pfleger¹, Udit Acharya^{1

2}, Yadu R Panthi^{1

2}, Miroslav Menšík¹, Alexander Zhigunov³, Muhammed A Thottappali^{1

2}, Martin Vala⁴, Aneta Marková⁴, Stanislav Stříteský⁴, Martin Weiter⁴, Martin Cigánek⁴, Jozef Krajčovič⁴, Karel Pauk⁵, Aleš Imramovský⁵, Alexandr Zaykov^{6

7}, Josef Michl^{6

8}

Affiliations

¹ Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic.
² Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic.
³ Department of X-ray and Neutron Structural Analysis, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic.
⁴ Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic.
⁵ Department of Organic Technology, Institute of Organic Chemistry and Technology at the University of Pardubice, Studentská 573, 532 10, Pardubice, Czech Republic.
⁶ Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic.
⁷ University of Chemistry and Technology, Technická 5, 16628, Prague 6, Czech Republic.
⁸ Department of Chemistry, University of Colorado, Boulder, Colorado, 80309-0215, USA.

PMID: 33332757
DOI: 10.1002/cplu.202000623

Abstract

The singlet fission (SF) process discovered in bis(thienyl)diketopyrrolopyrroles (TDPPs) can boost their potential for photovoltaics (PV). The crystal structures of TDPP analogs carrying n-hexyl, n-butyl, or 2-(adamant-1-yl)ethyl substituents are similar, but contain increasingly slipped stacked neighbor molecules. The observed SF rate constants, k_SF , (7±4), (9±3) and (5.6±1.9) ns^-1 for thin films of the three compounds, respectively, are roughly equal, but the triplet quantum yields vary strongly: (120±40), (160±40) and (70±16), respectively. The recent molecular pair model reproduces the near equality of all three k_SF at the crystal geometries and identifies all possible pair arrangements in which SF is predicted to be faster, by up to two orders of magnitude. However, it is also clear that the presently non-existent ability to predict the rates of processes competing with SF is pivotal for providing a guide for efforts to optimize the materials for PV.

Keywords: optical spectroscopy; photophysics; singlet fission; thin films; triplet excitons.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't