1,721,253 research outputs found
Temperature dependence of the spectral line-width of charge-transfer state emission in organic sola cells; static vs dynamic order
No full textOrganic indoor PV: vanishing surface recombination allows for robust device architecture
No full textThe authors acknowledge the financial support from the European Research Council (ERC, grant agreement 864625). B. S. acknowledges funding from the Research Foundation - Flanders (FWO) through a Senior Postdoctoral Fellowship (project: SOFIA, file no. 12AOC24N)
Understanding and Suppressing Non‐Radiative Recombination Losses in Non‐Fullerene Organic Solar Cells
Full text linkThe authors acknowledge financial support from the European Research Council (ERC, grant agreement 864625) and the European Union's Horizon 2020 research and innovation program under the Marie-Curie grant agreement no. 882794
Benzothiadiazole-based push-pull copolymers - Balancing synthetic complexity against organic solar cell efficiency
No full textThe authors thank the Research Foundation - Flanders (FWO Vlaanderen) for continuing financial support (PhD scholarship 1S98320N, projects G0D0118N, G0B2718N, 1S50820N, 11D2618N), as well as the European Research Council (ERC, grant agreement 864625)
Influence of dopant-host energy level offset on thermoelectric properties of doped organic semiconductors
No full textTemperature dependence of the spectral line-width of charge-transfer state emission in organic solar cells; static vs. dynamic disorder
No full textThe origin of energetic disorder in organic semiconductors and its impact on opto-electronic properties remains a topic of intense controversy. Particularly the disorder at electron donor-acceptor interfaces for organic photovoltaics is pivotal to understand as it is expected to affect photo-carrier generation, recombination and consequently device efficiency parameters. In this work we evaluate the temperature dependence of the line-shape of the photoluminescence (PL) and electroluminescence (EL) spectra of small molecule:fullerene blend devices, with the ambition to disentangle dynamic and static disorder contributions. The EL emission spectra are dominated by charge-transfer (CT) state emission and are confirmed to be of Gaussian character and almost completely voltage independent. More importantly, a strong line-width narrowing is persistently observed upon cooling, down to a certain material specific low temperature, below which the line-width remains constant. It is consequently clear that the main portion of the line-width measured at operating conditions of room temperature or higher, is originating from thermally activated, or dynamic, disorder. The observed temperature dependence of the high-energy emission tail can be fully described by taking into account high and low frequency molecular vibrational modes, without having to rely on static disorder. The presence of low frequency molecular modes with large Huang-Rhys factors results in a Gaussian line-shape, which is additionally broadened at high temperature by thermal population of high frequency intra-molecular modes. We therefore cast strong doubts regarding the commonly used assumption that single temperature optical measurements of absorption or emission tails are able to provide meaningful information regarding the shape of a static density of states tail.K. T. acknowledges the German Research Foundation (DFG) through project 382633022 (RECOLPER) and the Experimental Physics VI chair of Prof. Vladimir Dyakonov at Wurzburg University. J. B. acknowledges the DFG project VA 1035/5-1 (Photogen) and the Sachsische Aufbaubank through project no. 100325708 (Infrakart). The authors also acknowledge discussion on the topic with Robert Street, Thomas Kirchartz, Frank Ortmann and Carsten Deibel.Tvingstedt, K (corresponding author), Julius Maximilian Univ Wurzburg, Expt Phys 6, D-97074 Wurzburg, Germany.
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Ultra-precise photothermal measurements reveal near unity photoluminescence quantum yields of molecular emitters in solution
No full textThis work was funded by the European Research Council (ERC, grant agreement 864625) and the Special Research Fund (BOF) of Hasselt University BOF19OWB15
Relating the open-circuit voltage to interface molecular properties of donor:acceptor bulk heterojunction solar cells
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