64
M. Hiramoto
mobility has been observed in the direction parallel to the substrate owing to strong
π-π interactions (Fig. 3.15), this concept is suitable for the lateral device.
(d)
Electron Collecting
Electrode
(BCP/Ag)
H 2 Pc
(50 nm)
Hole Collecting
Electrode
(MoO 3 /Ag)
Sapphire substrate
h +
L e = 0.2 mm
0.1
0.2
0.3
0.4
Current / µA
1
Cross-sectional
current density / mA cm -2
0
0.001
— 0 V/cm
— 10 V/cm
— 20 V/cm
— 30 V/cm
PTCDI-C8
e -
0.005
10
5
A
B
C
Cross-sectional area
(50 nm
2 mm)
Inter electrode distance (L)
0.05 –0.4 mm
L / mm
L h = 0.4 mm
e -
Electron Collecting
Electrode
(BCP/Ag)
C 60
(50 nm)
Hole Collecting
Electrode
(MoO 3 /Ag)
Sapphire substrate
h
0.01
0.1
1
— 0 V/cm
— 10 V/cm
— 20 V/cm
— 30 V/cm
100
10
1000
Cross-sectional
current density / mA cm -2
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Current / µA
(a)
(c)
-1
-0.5
0
0.5
1
1.5
Voltage / V
1.0
0.8
0.6
0.4
0.2
-0.2
-0.4
L=0.05 mm
0.10 mm
0.20 mm
0.40 mm
0.50 mm
0.60 mm
Current / µA
(b)
A
B
C
h+
(50 nm
2 mm)
Inter electrode distance(L)
0.05 –0.6 mm
0
L / mm
Starting line
Starting line
0
Fig. 3.16 a Hole pathway unit cells with electrode distance (L) from 0.05 to 0.6 mm. C-plane singlecrystal sapphire substrates which were annealed at 1,200 °C for 1 h in air were used. b Dependence
of photocurrent magnitude on L under constant electric fields of 0 (black), 10 (red), 20 (green),
and 30 V·cm −1 (blue) between lateral electrodes. Current density calculated from area of cross
section of C8-BTBT film is shown on right vertical axis. c Current-voltage (J-V ) characteristics of
hole pathway unit cells. d Electron pathway unit cells with L from 0.05 to 0.4 mm. e Dependence
of photocurrent magnitude on L under constant electric field strengths of 0 (black), 10 (red), 20
(green), and 30 V·cm −1 (blue). Reproduced with permission from M. Kikuchi et al., ACS Appl.
Energy Mater., 2, 2087 (2019). Copyright 2019, American Chemical Society