Sub-picosecond charge-transfer at near-zero driving force in polymer:non-fullerene acceptor blends and bilayers

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Yufei Zhong - , Universität Bern (Autor:in)
  • Martina Causa’ - , Universität Bern (Autor:in)
  • Gareth John Moore - , Universität Bern (Autor:in)
  • Philipp Krauspe - , Universität Bern (Autor:in)
  • Bo Xiao - , Chinese Academy of Sciences (Autor:in)
  • Florian Günther - , University of São Paulo (Autor:in)
  • Jonas Kublitski - , Professur für Optoelektronik (Autor:in)
  • Rishi Shivhare - , Professur für Organische Bauelemente (cfaed) (Autor:in)
  • Johannes Benduhn - , Professur für Optoelektronik (Autor:in)
  • Eyal BarOr - , Universität Potsdam (Autor:in)
  • Subhrangsu Mukherjee - , National Institute of Standards and Technology (NIST) (Autor:in)
  • Kaila M. Yallum - , Universität Bern (Autor:in)
  • Julien Réhault - , Universität Bern (Autor:in)
  • Stefan C. B. Mannsfeld - , Professur für Organische Bauelemente (cfaed) (Autor:in)
  • Dieter Neher - , Universität Potsdam (Autor:in)
  • Lee J. Richter - , National Institute of Standards and Technology (NIST) (Autor:in)
  • Dean M. DeLongchamp - , National Institute of Standards and Technology (NIST) (Autor:in)
  • Frank Ortmann - , Computational Nanoelectronics (NFoG) (cfaed) (Autor:in)
  • Koen Vandewal - , Hasselt University (Autor:in)
  • Erjun Zhou - , Chinese Academy of Sciences (Autor:in)
  • Natalie Banerji - , Universität Bern (Autor:in)

Abstract

Organic photovoltaics based on non-fullerene acceptors (NFAs) show record efficiency of 16 to 17% and increased photovoltage owing to the low driving force for interfacial charge-transfer. However, the low driving force potentially slows down charge generation, leading to a tradeoff between voltage and current. Here, we disentangle the intrinsic charge-transfer rates from morphology-dependent exciton diffusion for a series of polymer:NFA systems. Moreover, we establish the influence of the interfacial energetics on the electron and hole transfer rates separately. We demonstrate that charge-transfer timescales remain at a few hundred femtoseconds even at near-zero driving force, which is consistent with the rates predicted by Marcus theory in the normal region, at moderate electronic coupling and at low re-organization energy. Thus, in the design of highly efficient devices, the energy offset at the donor:acceptor interface can be minimized without jeopardizing the charge-transfer rate and without concerns about a current-voltage tradeoff.

Details

OriginalspracheEnglisch
Aufsatznummer833
FachzeitschriftNature communications
Jahrgang11
PublikationsstatusVeröffentlicht - Dez. 2020
Peer-Review-StatusJa

Externe IDs

Scopus 85079335152

Schlagworte