Equilibrated charge carrier populations govern steady-state nongeminate recombination in disordered organic solar cells
We employed bias-assisted charge extraction techniques to investigate the transient and steady-state recombination of photogenerated charge carriers in complete devices of a disordered polymer-fullerene blend. Charge recombination is shown to be dispersive, with a significant slowdown of the recombi...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
March 4, 2019
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| In: |
The journal of physical chemistry letters
Year: 2019, Volume: 10, Issue: 6, Pages: 1374-1381 |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.9b00516 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1021/acs.jpclett.9b00516 |
| Author Notes: | Steffen Roland, Juliane Kniepert, John A. Love, Vikas Negi, Feilong Liu, Peter Bobbert, Armantas Melianas, Martijn Kemerink, Andreas Hofacker, and Dieter Neher |
| Summary: | We employed bias-assisted charge extraction techniques to investigate the transient and steady-state recombination of photogenerated charge carriers in complete devices of a disordered polymer-fullerene blend. Charge recombination is shown to be dispersive, with a significant slowdown of the recombination rate over time, consistent with the results from kinetic Monte Carlo simulations. Surprisingly, our experiments reveal little to no contributions from early time recombination of nonequilibrated charge carriers to the steady-state recombination properties. We conclude that energetic relaxation of photogenerated carriers outpaces any significant nongeminate recombination under application-relevant illumination conditions. With equilibrated charges dominating the steady-state recombination, quasi-equilibrium concepts appear suited for describing the open-circuit voltage of organic solar cells despite pronounced energetic disorder. |
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| Item Description: | Gesehen am 26.11.2019 Vom Autor zitiert als: Thermalized carrier populations govern steady state non-geminate recombination in disordered organic solar cells |
| Physical Description: | Online Resource |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.9b00516 |