TY - JOUR
T1 - Ultrafast photoinduced charge generation in conjugated polymers
AU - Moses, Daniel
AU - Dogariu, Arthur
AU - Heeger, Alan J.
N1 - Funding Information:
We are grateful to Prof. E.W. Van Stryland and Dr. D. McBranch for providing us with AgGaSe 2 crystal, and to Jian Wang for assistance with sample preparation. Dr. D. McBranch pointed out the importance of the different time scales observed for carrier decay and exciton decay. This research was supported by the Air Force Office of Scientific Research (Charles Lee, Program Officer) under F49620-99-1-0031.
PY - 2000/1/21
Y1 - 2000/1/21
N2 - Transient excited-state absorption measurements in the spectral region spanning the infrared active vibrational active (IRAV) modes in prototypical luminescent polymers, poly(phenylene vinylene), PPV, and poly[2-methoxy-5-(2-ethyl-hexyloxy)-(phenylene vinylene)], MEH-PPV, reveal charge carrier generation within 100 fs after photoexcitation. The photocarrier quantum efficiency in MEH-PPV is φo≈0.1 in zero applied electric field. There is no correlation between the temporal behavior of the photoinduced IRAV signals and the exciton lifetime. Thus, carriers are photoexcited directly and not generated via a secondary process from exciton annihilation. Our data indicate that the carrier recombination rate is sensitive to the strength of the inter-chain interaction.
AB - Transient excited-state absorption measurements in the spectral region spanning the infrared active vibrational active (IRAV) modes in prototypical luminescent polymers, poly(phenylene vinylene), PPV, and poly[2-methoxy-5-(2-ethyl-hexyloxy)-(phenylene vinylene)], MEH-PPV, reveal charge carrier generation within 100 fs after photoexcitation. The photocarrier quantum efficiency in MEH-PPV is φo≈0.1 in zero applied electric field. There is no correlation between the temporal behavior of the photoinduced IRAV signals and the exciton lifetime. Thus, carriers are photoexcited directly and not generated via a secondary process from exciton annihilation. Our data indicate that the carrier recombination rate is sensitive to the strength of the inter-chain interaction.
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U2 - 10.1016/S0009-2614(99)01316-0
DO - 10.1016/S0009-2614(99)01316-0
M3 - Article
AN - SCOPUS:0042528011
VL - 316
SP - 356
EP - 360
JO - Chemical Physics Letters
JF - Chemical Physics Letters
SN - 0009-2614
IS - 5-6
ER -