TY - JOUR
T1 - Importance of intramolecular electron spin relaxation in small molecule semiconductors
AU - Schulz, L.
AU - Willis, M.
AU - Nuccio, L.
AU - Shusharov, P.
AU - Fratini, S.
AU - Pratt, F. L.
AU - Gillin, W. P.
AU - Kreouzis, T.
AU - Heeney, M.
AU - Stingelin, N.
AU - Stafford, C. A.
AU - Beesley, D. J.
AU - Bernhard, C.
AU - Anthony, J. E.
AU - McKenzie, I.
AU - Lord, J. S.
AU - Drew, A. J.
PY - 2011/8/26
Y1 - 2011/8/26
N2 - Electron spin relaxation rate (eSR) is investigated on several organic semiconductors of different morphologies and molecular structures, using avoided level crossing muon spectroscopy as a local spin probe. We find that two functionalized acenes (polycrystalline tri(isopropyl)silyl-pentacene and amorphous 5,6,11,12-tetraphenyltetracene) exhibit eSRs with an Arrhenius-like temperature dependence, each with two characteristic energy scales similar to those expected from vibrations. Polycrystalline tris(8-hydroxyquinolate)gallium shows a similar behavior. The observed eSR for these molecules is no greater than 0.85 MHz at 300 K. The variety of crystal structures and transport regimes that these molecules possess, as well as the local nature of the probe, strongly suggest an intramolecular phenomenon general to many organic semiconductors, in contrast to the commonly assumed spin relaxation models based on intermolecular charge-carrier transport.
AB - Electron spin relaxation rate (eSR) is investigated on several organic semiconductors of different morphologies and molecular structures, using avoided level crossing muon spectroscopy as a local spin probe. We find that two functionalized acenes (polycrystalline tri(isopropyl)silyl-pentacene and amorphous 5,6,11,12-tetraphenyltetracene) exhibit eSRs with an Arrhenius-like temperature dependence, each with two characteristic energy scales similar to those expected from vibrations. Polycrystalline tris(8-hydroxyquinolate)gallium shows a similar behavior. The observed eSR for these molecules is no greater than 0.85 MHz at 300 K. The variety of crystal structures and transport regimes that these molecules possess, as well as the local nature of the probe, strongly suggest an intramolecular phenomenon general to many organic semiconductors, in contrast to the commonly assumed spin relaxation models based on intermolecular charge-carrier transport.
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U2 - 10.1103/PhysRevB.84.085209
DO - 10.1103/PhysRevB.84.085209
M3 - Article
AN - SCOPUS:80052439003
SN - 1098-0121
VL - 84
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 8
M1 - 085209
ER -