Abstract
We present photoexcitation studies of vacuum deposited neutral films of .alpha..omega.-substituted sexithiophene (.alpha.-6T) using photoinduced absorption (PA) and PA-detected magnetic resonance spectroscopy (PADMR). We find evidence for photoinduced polarons having spin 1/2, with two absorption bands at 0.80 and 1.54 eV, respectively, and with negative PADMR signal at g .apprxeq.2. Similarabsorption bands are observed in lightly p-doped sexithiophene and are interpreted as due to 6T.bul.+ radical cations. In addition, a PA band is found at 1.1 eV, which is shorter lived and decreases faster with increasing temperature than the polaron bands. As similar dication bands (6T.sup.2+) have been found in heavily-doped .alpha.-6T, we identify this band as due to spinless bipolarons.Evidence of charge conjugation symmetry breaking in .alpha.-6T is presented. Finally, we have identified triplet excitons with triplet-triplet transition energy at about 1.45 eV.
| Original language | American English |
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| Pages | Vol. 2: 1338-1342 |
| Number of pages | 5 |
| State | Published - 1996 |
| Event | ANTEC '96: Annual Technical Conference of the Society of Plastics Engineers 1996 - Duration: 1 Jan 1996 → 1 Jan 1996 |
Conference
| Conference | ANTEC '96: Annual Technical Conference of the Society of Plastics Engineers 1996 |
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| Period | 1/01/96 → 1/01/96 |
NREL Publication Number
- NREL/CP-590-25344