Efficient Free Triplet Generation Follows Singlet Fission in Diketo-pyrrolopyrrole Polymorphs with Goldilocks Coupling. Academic Article uri icon


  • Microcrystal electron diffraction, grazing incidence wide-angle scattering, and UV-Vis spectroscopy were used to determine the unit cell structure and the relative composition of dimethylated diketopyrrolopyrrole (MeDPP) H- and J-polymorphs within thin films subjected to vapor solvent annealing (VSA) for different times. Electronic structure and excited state deactivation pathways of the different polymorphs were examined by transient absorption spectroscopy, conductive probe atomic force microscopy, and molecular modeling. We find VSA initially converts amorphous films into mixtures of H- and J-polymorphs and promotes further conversion from H to J with longer VSA times. Though both polymorphs exhibit efficient SF to form coupled triplets, free triplet yields are higher in J-polymorph films compared to mixed films because coupling in J-aggregates is lower, and, in turn, more favorable for triplet decoupling.

published proceedings

  • J Phys Chem C Nanomater Interfaces

altmetric score

  • 1.5

author list (cited authors)

  • Levine, A. M., He, G., Bu, G., Ramos, P., Wu, F., Soliman, A., ... Braunschweig, A. B.

citation count

  • 3

complete list of authors

  • Levine, Andrew M||He, Guiying||Bu, Guanhong||Ramos, Pablo||Wu, Fanglue||Soliman, Aisha||Serrano, Jacqueline||Pietraru, Dorian||Chan, Christopher||Batteas, James D||Kowalczyk, Marta||Jang, Seogjoo J||Nannenga, Brent L||Sfeir, Matthew Y||Tsai, Esther HR||Braunschweig, Adam B

publication date

  • June 2021