68
M. Hiramoto
-0.02
0
0.02
0.04
0.06
0.08
-1.5 -1 -0.5 0 0.5 1 1.5
Voltage / V
(a)
2 layers
10 layers
4 layers
0
50
100
-100 -50
Electric field / Vcm -1
0
-25
25
50
75
100
(b)
Cross-sectional
current density / mA cm -2
13.5
135
1350
0.01
0.1
1
10
100
1000
Light intensity / mWcm
-2
Current density / mA cm -2
Cross-sectional
current density / mA cm -2
Slope = 1.02
Current density / mA cm - 2
-0.02
0
0.02
0.04
0.06
0.08
-1.5 -1 -0.5 0 0.5 1 1.5
(a)
10 layers
4 layers
0
50
100
-100 -50
-1
0
-
50
75
100
(b)
-
-2
13.5
135
1350
0.01
0.1
1
10
100
1000
-2
-2
-
-2
-
2 layers 4 layers
10 layers
PTCDI-C8
C8-BTBT
100
nm
e -
e -
h +
e -
h +
e -
h +
h +
10 nm
50 nm
(e)
C8-BTBT
molecule
25 nm
10 nm
PTCDI-C8
molecule
(d)
0.0001
0.001
0.01
0
2 0
4 0
6 0
IQE
420 nm
460 nm
480 nm
500 nm
520 nm
560 nm
350 400 450 500 550 600 650
2 layers
10 layers
4 layers
Absorbance
Internal Quantum Efficiency
(IQE) / %
Wavelength /nm
(c)
0
0.05
0.10
0.15
0.20
0
0.5
1.0
1.5
2.0
Thickness of PTCDI-C8 layer / nm
Fig. 3.19 a Current-voltage (J-V ) characteristics of lateral alternating multilayered junctions of
2-layered (black), 4-layered (blue), and 10-layered (red) devices. Photocurrent density per cell area
is shown on left vertical axis. Effective electric field in cell is shown on upper horizontal axis.
Photocurrent density per cross-sectional area of multilayered film is shown on right vertical axis.
Broken curve is dark current. b Dependence of short-circuit photocurrent density (J SC ) on simulated
solar light intensity between 0.25 and 5 suns (from 25 to 500 mW·cm −2 ) for 10-layered alternating
multilayered cell. c Action spectra of internal quantum efficiency (IQE) of J SC for each number
of layers. Absorption spectrum of film with a total thickness of C8-BTBT (50 nm) and PTCDI-C8
(50 nm) is also shown (black curve). d Semilogarithmic plots of dependence of IQE at various
wavelengths on PTCDI-C8 layer thickness. e Active region (red) and dead region (pink) of exciton
collection in 2-, 4-, and 10-layered cells. Layer thickness of 10 nm corresponds to 5 and 3 molecules
of PTCDI-C8 and C8-BTBT, respectively. Reproduced with permission from M. Kikuchi et al.,
ACS Appl. Energy Mater., 2, 2087 (2019). Copyright 2019, American Chemical Society
M. Hiramoto
-0.02
0
0.02
0.04
0.06
0.08
-1.5 -1 -0.5 0 0.5 1 1.5
Voltage / V
(a)
2 layers
10 layers
4 layers
0
50
100
-100 -50
Electric field / Vcm -1
0
-25
25
50
75
100
(b)
Cross-sectional
current density / mA cm -2
13.5
135
1350
0.01
0.1
1
10
100
1000
Light intensity / mWcm
-2
Current density / mA cm -2
Cross-sectional
current density / mA cm -2
Slope = 1.02
Current density / mA cm - 2
-0.02
0
0.02
0.04
0.06
0.08
-1.5 -1 -0.5 0 0.5 1 1.5
(a)
10 layers
4 layers
0
50
100
-100 -50
-1
0
-
50
75
100
(b)
-
-2
13.5
135
1350
0.01
0.1
1
10
100
1000
-2
-2
-
-2
-
2 layers 4 layers
10 layers
PTCDI-C8
C8-BTBT
100
nm
e -
e -
h +
e -
h +
e -
h +
h +
10 nm
50 nm
(e)
C8-BTBT
molecule
25 nm
10 nm
PTCDI-C8
molecule
(d)
0.0001
0.001
0.01
0
2 0
4 0
6 0
IQE
420 nm
460 nm
480 nm
500 nm
520 nm
560 nm
350 400 450 500 550 600 650
2 layers
10 layers
4 layers
Absorbance
Internal Quantum Efficiency
(IQE) / %
Wavelength /nm
(c)
0
0.05
0.10
0.15
0.20
0
0.5
1.0
1.5
2.0
Thickness of PTCDI-C8 layer / nm
Fig. 3.19 a Current-voltage (J-V ) characteristics of lateral alternating multilayered junctions of
2-layered (black), 4-layered (blue), and 10-layered (red) devices. Photocurrent density per cell area
is shown on left vertical axis. Effective electric field in cell is shown on upper horizontal axis.
Photocurrent density per cross-sectional area of multilayered film is shown on right vertical axis.
Broken curve is dark current. b Dependence of short-circuit photocurrent density (J SC ) on simulated
solar light intensity between 0.25 and 5 suns (from 25 to 500 mW·cm −2 ) for 10-layered alternating
multilayered cell. c Action spectra of internal quantum efficiency (IQE) of J SC for each number
of layers. Absorption spectrum of film with a total thickness of C8-BTBT (50 nm) and PTCDI-C8
(50 nm) is also shown (black curve). d Semilogarithmic plots of dependence of IQE at various
wavelengths on PTCDI-C8 layer thickness. e Active region (red) and dead region (pink) of exciton
collection in 2-, 4-, and 10-layered cells. Layer thickness of 10 nm corresponds to 5 and 3 molecules
of PTCDI-C8 and C8-BTBT, respectively. Reproduced with permission from M. Kikuchi et al.,
ACS Appl. Energy Mater., 2, 2087 (2019). Copyright 2019, American Chemical Society