Homogeneous alignment of films on rubbed polyimide results in a more than one order of magnitude increase in time-of-flight hole mobility normal to the alignment direction. We find at an electric field of Hole transport is found to be nondispersive, indicating a low degree of energetic disorder.
REFERENCES
1.
H.
Sirringhaus
, N.
Tessler
, and R. H.
Friend
, Science
280
, 1741
(1998
).2.
3.
J. H.
Burroughes
, D. D. C.
Bradley
, A. R.
Brown
, R. N.
Marks
, K.
Mackay
, R. H.
Friend
, P. L.
Burn
, and A. B.
Holmes
, Nature (London)
347
, 539
(1990
).4.
A. J.
Campbell
, D. D. C.
Bradley
, and D. G.
Lidzey
, J. Appl. Phys.
82
, 6326
(1997
).5.
D.
Adam
, P.
Schuhmacher
, J.
Simmerer
, L.
Häussling
, K.
Siemensmeyer
, K. H.
Etzbach
, H.
Ringsdorf
, and D.
Haarer
, Nature (London)
371
, 141
(1994
).6.
7.
8.
H.
Tokuhisa
, M.
Era
, and T.
Tsutsui
, Appl. Phys. Lett.
72
, 2639
(1998
).9.
T.
Christ
, V.
Stümpflen
, and J. H.
Wendorff
, Macromol. Rapid Commun.
18
, 93
(1997
).10.
F.
Cacialli
, R.
Daik
, P.
Dounis
, W. J.
Feast
, R. H.
Friend
, N. D.
Haylett
, C. P.
Jarrett
, C.
Schönenberger
, J. A.
Stephens
, and G.
Widawski
, Philos. Trans. R. Soc. London, Ser. A
355
, 707
(1997
).11.
A.
Grice
, D. D. C.
Bradley
, M. T.
Bernius
, M.
Inbasekaran
, W. W.
Wu
, and E. P.
Woo
, Appl. Phys. Lett.
73
, 629
(1998
).12.
M.
Grell
, D. D. C.
Bradley
, M.
Inbasekaran
, and E. P.
Woo
, Adv. Mater.
9
, 798
(1997
).13.
M.
Redecker
, D. D. C.
Bradley
, M.
Inbasekaran
, and E. P.
Woo
, Appl. Phys. Lett.
73
, 1565
(1998
).14.
S.
Janietz
, D. D. C.
Bradley
, M.
Grell
, M.
Inbasekaran
, and E. P.
Woo
, Appl. Phys. Lett.
73
, 2453
(1998
).15.
M.
Grell
, D. D. C.
Bradley
, X.
Long
, T.
Chamberlain
, M.
Inbasekaran
, and E. P.
Woo
, Acta Polym.
49
, 439
(1998
).16.
17.
The 30 nm thickness is some 10 nm less than that recommended by the manufacturer as the minimum required to ensure good electrical insulation properties. Our previous experience has shown that this thickness is sufficient to achieve good alignment. Structures made with a 30 nm thickness polyimide layer on an ITO substrate and with an electron injection cathode (e.g., aluminum) function as LEDs indicating that carriers do transport between the ITO substrate and the aligned PFO film. The details of this process are under more detailed investigation.
18.
The time required for alignment was estimated by extrapolation from alignment studies performed on films of thickness 50 nm.
19.
20.
P. M.
Borsenberger
, L.
Pautmeier
, and H.
Bässler
, J. Chem. Phys.
94
, 5447
(1991
).21.
This content is only available via PDF.
© 1999 American Institute of Physics.
1999
American Institute of Physics
You do not currently have access to this content.
