Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Spin-dependent recombination of the charge-transfer state in photovoltaic polymer/fullerene blends. / Lukina, E. A.; Reijerse, E.; Lubitz, W. и др.
в: Molecular Physics, Том 117, № 19, 01.01.2019, стр. 2654-2663.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Spin-dependent recombination of the charge-transfer state in photovoltaic polymer/fullerene blends
AU - Lukina, E. A.
AU - Reijerse, E.
AU - Lubitz, W.
AU - Kulik, L. V.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Q-band electron spin echo (ESE) spectroscopy was applied for studying the spin-dependent recombination of charge transfer (CT) states in the benchmark organic photovoltaics (OPV) blend of poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl C61 butyric acid methyl ester (P3HT/PC60BM). Selective microwave excitation and a special protocol for ESE data treatment allowed to suppress the ESE signal of thermalised polarons and weakly coupled CT states and to address CT states with a relatively short distance between positive and negative polarons (1.5 nm < r < 2.5 nm). Inversion of the in-phase ESE signal with increase of the delay after laser flash was observed for the regioregular P3HT +/PC60BM − CT state at a temperature of 40 K. This effect is very similar to the inversion of the time resolved (TR) EPR spectrum of the same system obtained previously. Both effects can be explained by spin-dependent recombination of the CT state, with the recombination via the triplet channel proceeding much slower than via the singlet channel. For the regiorandom P3HT+/PC60BM − CT state no ESE sign inversion was observed in an analogous experiment. The result suggests the importance of CT state formation via a triplet exciton, a process which was not considered previously for the P3HT/PC60BM blend.
AB - Q-band electron spin echo (ESE) spectroscopy was applied for studying the spin-dependent recombination of charge transfer (CT) states in the benchmark organic photovoltaics (OPV) blend of poly(3-hexylthiophene-2,5-diyl) and [6,6]-phenyl C61 butyric acid methyl ester (P3HT/PC60BM). Selective microwave excitation and a special protocol for ESE data treatment allowed to suppress the ESE signal of thermalised polarons and weakly coupled CT states and to address CT states with a relatively short distance between positive and negative polarons (1.5 nm < r < 2.5 nm). Inversion of the in-phase ESE signal with increase of the delay after laser flash was observed for the regioregular P3HT +/PC60BM − CT state at a temperature of 40 K. This effect is very similar to the inversion of the time resolved (TR) EPR spectrum of the same system obtained previously. Both effects can be explained by spin-dependent recombination of the CT state, with the recombination via the triplet channel proceeding much slower than via the singlet channel. For the regiorandom P3HT+/PC60BM − CT state no ESE sign inversion was observed in an analogous experiment. The result suggests the importance of CT state formation via a triplet exciton, a process which was not considered previously for the P3HT/PC60BM blend.
KW - conjugated polymer
KW - electron spin echo
KW - fullerene PC60BM
KW - geminate recombination
KW - Organic photovoltaics
KW - SELECTIVE EXCITATION
KW - ENERGY
KW - PULSED EPR
KW - ECHO
KW - SEPARATED STATE
KW - DOUBLE-QUANTUM COHERENCE
KW - CORRELATED RADICAL PAIRS
KW - P3HT/PC70BM COMPOSITE
KW - DYNAMICS
KW - PHOTOSYNTHESIS
UR - http://www.scopus.com/inward/record.url?scp=85057329673&partnerID=8YFLogxK
U2 - 10.1080/00268976.2018.1548713
DO - 10.1080/00268976.2018.1548713
M3 - Article
AN - SCOPUS:85057329673
VL - 117
SP - 2654
EP - 2663
JO - Molecular Physics
JF - Molecular Physics
SN - 0026-8976
IS - 19
ER -
ID: 17565317