Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Geminate recombination in organic photovoltaic blend PCDTBT/PC71BM studied by out-of-phase electron spin echo spectroscopy. / Beletskaya, E. A.; Lukina, E. A.; Uvarov, M. N. и др.
в: Journal of Chemical Physics, Том 152, № 4, 044706, 31.01.2020.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Geminate recombination in organic photovoltaic blend PCDTBT/PC71BM studied by out-of-phase electron spin echo spectroscopy
AU - Beletskaya, E. A.
AU - Lukina, E. A.
AU - Uvarov, M. N.
AU - Popov, A. A.
AU - Kulik, L. V.
PY - 2020/1/31
Y1 - 2020/1/31
N2 - The key process in organic solar cell operation is charge separation under light illumination. Due to the low dielectric constant of organic materials, the Coulomb attraction energy within the interfacial charge-transfer state (CTS) is larger than the thermal energy. Understanding the mechanism of charge separation at the organic donor/acceptor interface still remains a challenge and requires knowledge of the CTS temporal evolution. To address this problem, the CTS in the benchmark photovoltaic blend PCDTBT/PC71BM was studied by the out-of-phase Electron Spin Echo (ESE). The protocol for determining the CTS geminate recombination rate for certain electron-hole distances was developed. Simulating the out-of-phase ESE trace for the CTS in the PCDTBT/PC71BM blend allows precise determination of the electron-hole distance distribution function and its evolution with the increase in the delay after the laser flash. Distances of charge separation up to 6 nm were detected upon thermalization at a temperature of 20 K. Assuming the exponential decay of the recombination rate, the attenuation factor β = 0.08 Å-1 is estimated for the PCDTBT/PC71BM blend. Such a low attenuation factor is probably caused by a high degree of hole delocalization along the PCDTBT chain.
AB - The key process in organic solar cell operation is charge separation under light illumination. Due to the low dielectric constant of organic materials, the Coulomb attraction energy within the interfacial charge-transfer state (CTS) is larger than the thermal energy. Understanding the mechanism of charge separation at the organic donor/acceptor interface still remains a challenge and requires knowledge of the CTS temporal evolution. To address this problem, the CTS in the benchmark photovoltaic blend PCDTBT/PC71BM was studied by the out-of-phase Electron Spin Echo (ESE). The protocol for determining the CTS geminate recombination rate for certain electron-hole distances was developed. Simulating the out-of-phase ESE trace for the CTS in the PCDTBT/PC71BM blend allows precise determination of the electron-hole distance distribution function and its evolution with the increase in the delay after the laser flash. Distances of charge separation up to 6 nm were detected upon thermalization at a temperature of 20 K. Assuming the exponential decay of the recombination rate, the attenuation factor β = 0.08 Å-1 is estimated for the PCDTBT/PC71BM blend. Such a low attenuation factor is probably caused by a high degree of hole delocalization along the PCDTBT chain.
KW - CORRELATED RADICAL PAIRS
KW - PHOTOSYNTHETIC REACTION CENTERS
KW - INDUCED CHARGE SEPARATION
KW - DOUBLE-QUANTUM COHERENCE
KW - LONG-RANGE ELECTRON
KW - DISTANCE DETERMINATION
KW - P3HT/PC70BM COMPOSITE
KW - PHOTOSYSTEM-I
KW - DYNAMICS
KW - EPR
UR - http://www.scopus.com/inward/record.url?scp=85078681425&partnerID=8YFLogxK
U2 - 10.1063/1.5131855
DO - 10.1063/1.5131855
M3 - Article
C2 - 32007084
AN - SCOPUS:85078681425
VL - 152
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 4
M1 - 044706
ER -
ID: 23262573