300
a
b
200
II
II
×
⊥
⊥
100
10 –2
10 –3
10 –4
μ [cm
2
/Vs]
μ
ll /
μ
⊥
I
d [nA]
0
–50
1000/T [K –1 ]
3.5
4
4.5
5
5.5
5
4
3
–40 –30
V g [V]
–20
V sd =–60V
–10
0
Fig. 7 (a) Transfer
characteristics (Vsd = À60 V)
of aligned P7 TFTs with
channels parallel (upward
triangles) and perpendicular
(downward triangles) to the
alignment direction. Circles
show corresponding data for a
nonaligned device. (b)
Temperature dependence of
the linear (open symbols) and
saturated (closed symbols)
mobility (μ) and mobility
anisotropy (μ k /μ ⊥ ) of devices
with channels parallel and
perpendicular to the alignment
direction. (Reproduced with
permission from Sirringhaus
et al. (2000). Copyright 2000
The American Institute of
Physics)
q 0
c
z
Fig. 8 Relation between the
molecular axis c and the
alignment direction z.
(Reproduced with permission
from Knaapila et al. (2005a).
Copyright 2005 The
American Chemical Society)
11 Liquid Crystalline Conjugated Polymers
329