Jump to main content
Jump to site search

Issue 11, 2016
Previous Article Next Article

Enhanced organic solar cells efficiency through electronic and electro-optic effects resulting from charge transfers in polymer hole transport blends

Author affiliations

Abstract

We demonstrate that blending fluorinated molecules in PEDOT:PSS hole transport layers (HTL) induces charge transfers which impact on both charge extraction and photogeneration within organic photovoltaic (OPV) devices. OPVs fabricated with modified HTL and two photoactive polymer blends led systematically to power conversion efficiencies (PCE) increases, with PTB7:PC70BM blend exhibiting PCE of ∼8.3%, i.e. ∼15% increase compared to pristine HTL devices. A reduced device-to-device characteristics variations was also noticed when fluorinated additives were used to modify the PEDOT:PSS. Shading lights onto the effect of HTL fluorination, we show that the morphology of the polymer:PCBM blends remains surprisingly unaffected by the fluorinated HTL surface energy but that, instead, the OPVs are impacted not only by the HTL electronic properties (work function, dipole layer, open circuit voltage, charge transfer dynamic) but also by alteration of the complex refractive indices (photogeneration, short circuit current density, external quantum efficiencies, electro-optic modelling). Both mechanisms find their origin in fluorination induced charge transfers. This work points towards fluorination as a promising strategy toward combining both external quantum efficiency modulation and power conversion efficiency enhancement in OPVs. Charge transfers could also be used more broadly to tune the optical constants and electric field distribution, as well as to reduce interfacial charge recombinations within OPVs.

Graphical abstract: Enhanced organic solar cells efficiency through electronic and electro-optic effects resulting from charge transfers in polymer hole transport blends

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 24 Jan 2016, accepted on 22 Feb 2016 and first published on 24 Feb 2016


Article type: Paper
DOI: 10.1039/C6TA00677A
Citation: J. Mater. Chem. A, 2016,4, 4252-4263
  •   Request permissions

    Enhanced organic solar cells efficiency through electronic and electro-optic effects resulting from charge transfers in polymer hole transport blends

    C. T. Howells, K. Marbou, H. Kim, K. J. Lee, B. Heinrich, S. J. Kim, A. Nakao, T. Aoyama, S. Furukawa, J. Kim, E. Kim, F. Mathevet, S. Mery, I. D. W. Samuel, A. Al Ghaferi, M. S. Dahlem, M. Uchiyama, S. Y. Kim, J. W. Wu, J. Ribierre, C. Adachi, D. Kim and P. André, J. Mater. Chem. A, 2016, 4, 4252
    DOI: 10.1039/C6TA00677A

Search articles by author