Spin Signature of Photoexcitations in Sexithiophene

P. A. Lane; X. Wei; Z. V. Vardeny; J. Poplawski; E. Ehrenfreund; M. Ibrahim; A. J. Frank

doi:10.1016/0379-6779(95)03419-K

Spin Signature of Photoexcitations in Sexithiophene

P. A. Lane, X. Wei, Z. V. Vardeny, J. Poplawski, E. Ehrenfreund, M. Ibrahim, A. J. Frank

Chemistry and Nanoscience

Research output: Contribution to journal › Article › peer-review

28 Scopus Citations

Abstract

We present photoexcitation studies of vacuum-deposited neutral films of sexithiophene (6T) using photoinduced absorption spectroscopy and photoinduced absorption detected magnetic resonance (PADMR) techniques. We find evidence for photoinduced polarons (photoexcited 'radical ions') having spin 1/2, with two absorption bands at 0.80 and 1.54 eV, respectively, and with negative PADMR signal at g≃2. Similar absorption bands are observed in lightly p-doped 6T, and are interpreted as due to 6T^̇+ radical cations. In addition, a photoinduced absorption band is found at about 1.1 eV, which is shorter lived and decreases faster with increasing temperature than the polaron bands. We identify this band as due to spinless bipolarons (photoexcited 'di-ions'). A similar di-cation band has been identified in heavily p-doped 6T. Finally, we have identified triplet excitons (S=1) with triplet-triplet transition energy at about 1.45 eV.

Original language	American English
Pages (from-to)	57-60
Number of pages	4
Journal	Synthetic Metals
Volume	76
Issue number	1-3
DOIs	https://doi.org/10.1016/0379-6779(95)03419-K https://doi.org/10.1016/0379-6779(95)03419-K
State	Published - 1996

NREL Publication Number

NREL/JA-21423

Keywords

Photoexcitation
Sexithiophene
Spin

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@article{b6cbb400800f4aa89909354e8096f85d,

title = "Spin Signature of Photoexcitations in Sexithiophene",

abstract = "We present photoexcitation studies of vacuum-deposited neutral films of sexithiophene (6T) using photoinduced absorption spectroscopy and photoinduced absorption detected magnetic resonance (PADMR) techniques. We find evidence for photoinduced polarons (photoexcited 'radical ions') having spin 1/2, with two absorption bands at 0.80 and 1.54 eV, respectively, and with negative PADMR signal at g≃2. Similar absorption bands are observed in lightly p-doped 6T, and are interpreted as due to 6{\.T}+ radical cations. In addition, a photoinduced absorption band is found at about 1.1 eV, which is shorter lived and decreases faster with increasing temperature than the polaron bands. We identify this band as due to spinless bipolarons (photoexcited 'di-ions'). A similar di-cation band has been identified in heavily p-doped 6T. Finally, we have identified triplet excitons (S=1) with triplet-triplet transition energy at about 1.45 eV.",

keywords = "Photoexcitation, Sexithiophene, Spin",

author = "Lane, {P. A.} and X. Wei and Vardeny, {Z. V.} and J. Poplawski and E. Ehrenfreund and M. Ibrahim and Frank, {A. J.}",

year = "1996",

doi = "10.1016/0379-6779(95)03419-K",

language = "American English",

volume = "76",

pages = "57--60",

journal = "Synthetic Metals",

issn = "0379-6779",

publisher = "Elsevier BV",

number = "1-3",

}

TY - JOUR

T1 - Spin Signature of Photoexcitations in Sexithiophene

AU - Lane, P. A.

AU - Wei, X.

AU - Vardeny, Z. V.

AU - Poplawski, J.

AU - Ehrenfreund, E.

AU - Ibrahim, M.

AU - Frank, A. J.

PY - 1996

Y1 - 1996

N2 - We present photoexcitation studies of vacuum-deposited neutral films of sexithiophene (6T) using photoinduced absorption spectroscopy and photoinduced absorption detected magnetic resonance (PADMR) techniques. We find evidence for photoinduced polarons (photoexcited 'radical ions') having spin 1/2, with two absorption bands at 0.80 and 1.54 eV, respectively, and with negative PADMR signal at g≃2. Similar absorption bands are observed in lightly p-doped 6T, and are interpreted as due to 6Ṫ+ radical cations. In addition, a photoinduced absorption band is found at about 1.1 eV, which is shorter lived and decreases faster with increasing temperature than the polaron bands. We identify this band as due to spinless bipolarons (photoexcited 'di-ions'). A similar di-cation band has been identified in heavily p-doped 6T. Finally, we have identified triplet excitons (S=1) with triplet-triplet transition energy at about 1.45 eV.

AB - We present photoexcitation studies of vacuum-deposited neutral films of sexithiophene (6T) using photoinduced absorption spectroscopy and photoinduced absorption detected magnetic resonance (PADMR) techniques. We find evidence for photoinduced polarons (photoexcited 'radical ions') having spin 1/2, with two absorption bands at 0.80 and 1.54 eV, respectively, and with negative PADMR signal at g≃2. Similar absorption bands are observed in lightly p-doped 6T, and are interpreted as due to 6Ṫ+ radical cations. In addition, a photoinduced absorption band is found at about 1.1 eV, which is shorter lived and decreases faster with increasing temperature than the polaron bands. We identify this band as due to spinless bipolarons (photoexcited 'di-ions'). A similar di-cation band has been identified in heavily p-doped 6T. Finally, we have identified triplet excitons (S=1) with triplet-triplet transition energy at about 1.45 eV.

KW - Photoexcitation

KW - Sexithiophene

KW - Spin

UR - http://www.scopus.com/inward/record.url?scp=0029736123&partnerID=8YFLogxK

U2 - 10.1016/0379-6779(95)03419-K

DO - 10.1016/0379-6779(95)03419-K

M3 - Article

AN - SCOPUS:0029736123

SN - 0379-6779

VL - 76

SP - 57

EP - 60

JO - Synthetic Metals

JF - Synthetic Metals

IS - 1-3

ER -

Spin Signature of Photoexcitations in Sexithiophene

Abstract

NREL Publication Number

Keywords

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