URN to cite this document: urn:nbn:de:bvb:703-epub-7293-9
Title data
Kroh, Daniel ; Athanasopoulos, Stavros ; Nádaždy, Vojtech ; Kahle, Frank-Julian ; Bässler, Heinz ; Köhler, Anna:
An Impedance Study of the Density of States Distribution in Blends of PM6:Y6 in Relation to Barrierless Dissociation of CT States.
In: Advanced Functional Materials.
(2023)
.
- 2302520.
ISSN 1616-3028
DOI der Verlagsversion: https://doi.org/10.1002/adfm.202302520
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Abstract
Abstract In an endeavor to understand why the dissociation of charge-transfer (CT) states in a PM6:Y6 solar-cell is not a thermally activated process, measurements of energy-resolved impedance as well as of intrinsic photoconduction are employed. This study determines the density of states distributions of the pertinent HOMO and LUMO states and obtains a Coulomb binding energy (Eb,CT) of ≈150 meV. This is 250 meV lower than the value expected for a pair of localized charges with 1 nm separation. The reason is that the hole is delocalized in the polymer and the electron is shared among Y6 molecules forming a J-like aggregate. There are two key reasons why this binding energy of the CT state is not reflected in the temperature dependence of the photocurrent of PM6:Y6-diode: i) The e–h dissociation in a disordered system is a multi-step process whose activation energy is principally different from the binding energy of the CT state and can be substantially less than Eb,CT, and ii) since dissociation of the CT state competes with its intrinsic decay, the dissociation yield saturates once the rate of dissociation grossly exceeds the rate of intrinsic decay. This study argues that these conditions are met in a PM6:Y6-solar cell.
Further data
Item Type: | Article in a journal |
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Keywords: | aggregates; exciton dissociation; organic solar cell |
DDC Subjects: | 500 Science > 530 Physics |
Institutions of the University: | Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter > Chair Experimental Physics II - Optoelectronics of Soft Matter - Univ.-Prof. Dr. Anna Köhler Faculties Faculties > Faculty of Mathematics, Physics und Computer Science |
Language: | English |
Originates at UBT: | Yes |
URN: | urn:nbn:de:bvb:703-epub-7293-9 |
Date Deposited: | 09 Nov 2023 06:01 |
Last Modified: | 09 Nov 2023 06:01 |
URI: | https://epub.uni-bayreuth.de/id/eprint/7293 |