A triphenylamine-based push-pull – σ – C60 dyad as photoactive molecular material for single-component organic solar cells: synthesis, characterizations and photophysical properties
Balawi, Ahmed H.
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Materials Science and Engineering Program
KAUST Solar Center (KSC)
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AbstractA push-pull – σ – C60 molecular dyad was synthesized via Huisgen-type click-chemistry and used as photoactive material for single-component organic solar cells. Steady-state photoluminescence (PL) experiments of the dyad in solution show a significant quenching of the emission of the push-pull moiety. Spin-casting of a solution of the dyad results in homogenous and smooth thin-films, which exhibit complete PL quenching in line with ultrafast photo-induced electron-transfer in the solid-state. Spectro-electrochemistry reveals the optical signatures of radical cations and radical anions. Evaluation of the charge carrier mobility by space-charge limited current measurements gives an electron-mobility of μe = 4.3 × 10-4 cm2 V-1 s-1, ca. 50 times higher than the hole-mobility. Single-component organic solar cells yield an open-circuit voltage Voc of 0.73 V and a short-circuit current density of 2.1 mA cm-2 however, a poor fill-factor FF (29%) is obtained, resulting in low power conversion efficiency of only 0.4%. Combined TA and time-delayed collection field (TDCF) experiments show mostly ultrafast photon-to-charge conversion and a small component of diffusion-limited exciton dissociation, revealing the presence of pure fullerene domains. Furthermore, a strong field dependence of charge generation is observed, governing the device fill factor, which is further reduced by a competition between extraction and fast recombination of separated charges.
CitationLabrunie A, Gorenflot J, Babics M, Aleveque O, Dabos-Seignon S, et al. (2018) A triphenylamine-based push-pull – σ – C60 dyad as photoactive molecular material for single-component organic solar cells: synthesis, characterizations and photophysical properties. Chemistry of Materials. Available: http://dx.doi.org/10.1021/acs.chemmater.8b01117.
SponsorsThe RFI LUMOMAT from the Région Pays de la Loire is acknowledged for the PhD grant of A. Labrunie. We thank also the PIAM (Plateforme d’Ingénierie et Analyses Moléculaires) of the University of Angers for the characterization of organic compounds and R. Mallet, from the SCIAM of the University of Angers for TEM experiments. Jonhson Mattey is acknowledged for the gift of PdCl2 used for the preparation of Pd(PPh3)4 catalyst. The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). M. Wohlfahrt acknowledges a VSRP internship from KAUST.
PublisherAmerican Chemical Society (ACS)
JournalChemistry of Materials