Jump to main content
Jump to site search

Issue 8, 2012
Previous Article Next Article

Modeling geminate pair dissociation in organic solar cells: high power conversion efficiencies achieved with moderate optical bandgaps

Author affiliations

Abstract

We propose a model for geminate electron–hole dissociation in organic photovoltaic (OPV) cells and show how power conversion efficiencies greater than those currently achieved might be realized via design strategies employing moderate optical bandgaps and enhanced charge delocalization near the donor–acceptor interface. Applying this model to describing geminate electron–hole dissociation via charge transfer (CT) states, we find good agreement with recently published high-efficiency experimental data. The optimal bandgap for current-generation organic active layer materials is argued to be ∼1.7 eV – significantly greater than in previous analyses, including the Shockley–Queisser approach based upon non-excitonic solar cell dynamics. For future higher efficiency OPVs, the present results show that the optimal bandgap should be slightly lower, ∼1.6 eV. Finally, these results support design strategies aimed at enhancing mobility near the donor–acceptor interface and reducing the electron–hole binding energy, rather than striving to further reduce the bandgap.

Graphical abstract: Modeling geminate pair dissociation in organic solar cells: high power conversion efficiencies achieved with moderate optical bandgaps

Back to tab navigation

Supplementary files

Publication details

The article was received on 14 Feb 2012, accepted on 01 May 2012 and first published on 01 May 2012


Article type: Paper
DOI: 10.1039/C2EE21376A
Citation: Energy Environ. Sci., 2012,5, 8343-8350
  •   Request permissions

    Modeling geminate pair dissociation in organic solar cells: high power conversion efficiencies achieved with moderate optical bandgaps

    J. D. Servaites, B. M. Savoie, J. B. Brink, T. J. Marks and M. A. Ratner, Energy Environ. Sci., 2012, 5, 8343
    DOI: 10.1039/C2EE21376A

Search articles by author

Spotlight

Advertisements