Upload
hadat
View
214
Download
0
Embed Size (px)
Citation preview
Supplementary Figure 1. (a) Thermogravimetric analysis (10 °C min-1) and (b) differential
scanning calorimetry (5 °C min-1) of EH-IDTBR and O-IDTBR measured under nitrogen.
Thermograms are offset vertically for clarity.
Supplementary Figure 2. Chemical structures and minimum energy conformations of (a)
FBR and (b) IDTBR calculated (with methyl replacing n-octyl or 2-ethylhexyl groups) using
Gaussian (B3LYP/6-31G*) to visualize the LUMO and HOMO distributions.
0 50 100 150 200 250
Hea
t Flo
w, E
ndo
up
Temperature (°C)
O-IDTBR EH-IDTBR
heating
cooling
100 200 300 400 500 60020
30
40
50
60
70
80
90
100
110
We
igh
t L
oss
(%
)
Temperature (°C)
EH-IDTBR O-IDTBR
a b
HOMO
LUMOLUMO
a" b"
S
S
R R
R RN SN
NSN
SN S N
S
O
O
S
R = n-octyl O-IDTBRR= 2-ethylhexyl EH-IDTBR
R R
NS N
NSNSN
S N
O
S
O
SR = n-octyl FBR
HOMO
Supplementary Figure 3. (a) Absorption coefficients α of EH-IDTBR in the thin film
compared with a selection of low bandgap donor polymers (structures shown in
Supplementary Figure 16), where α was calculated with the equation α =1/d*ln(1/T); (b) UV-
vis absorption spectra of O-IDTBR thin films spin-coated from 10 mg ml-1 chlorobenzene
solution, as-cast and with 10 min annealing at different temperatures.
Supplementary Figure 4: Normalised UV-vis absorption spectra of as-cast IDTBR thin
films compared with that of PC60BM.
400 600 800 10000.0
0.2
0.4
0.6
0.8
1.0
Nor
mal
ised
Ab
sorp
tion
Wavelength (nm)
as-cast 110 °C 120 °C 130 °C 140 °C
400 500 600 700 8000
1
2
3
4
5
PTB7 PCE-10 PCE-11 EH-IDTBR
Abs
orpt
ion
Coe
ffic
ient
(105 c
m-1)
Wavelength (nm)
a b
300 400 500 600 700 800 900 10000.0
0.2
0.4
0.6
0.8
1.0
1.2
Nor
mal
ised
Thi
n Fi
lm A
bsor
ptio
n
Wavelength (nm)
O-IDTBR EH-IDTBR PC60BM
Supplementary Figure 5: (a) J-V characteristics and (b) EQE spectra for IDTBR:P3HT
devices compared to reference PC60BM:P3HT device measured at 100 mW cm-2 illumination.
Supplementary Figure 6. J-V characteristics of O-IDTBR:P3HT devices with different
active areas measured under 100 mW cm-2 illumination.
a b
400 500 600 700 800 9000.0
0.2
0.4
0.6
0.8
EQ
E
Wavelength (nm)
EH-IDTBR:P3HT O-IDTBR:P3HT PC60BM:P3HT
-0.4 -0.2 0.0 0.2 0.4 0.6 0.8
-15
-12
-9
-6
-3
0
3C
urr
ent D
ensi
ty (m
A c
m-2
)
Voltage (V)
EH-IDTBR:P3HT O-IDTBR:P3HT PC60BM:P3HT
-0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0-18
-15
-12
-9
-6
-3
0
3
Cur
rent
Den
sity
(mA
cm
-2)
Voltage (V)
0.045 cm2
0.15 cm2
0.75 cm2
1.5 cm2
Supplementary Figure 7. Specular XRD of (a) O-IDTBR and (b) EH-IDTBR films as-cast
and with annealing at 110 °C and 130 °C.
Supplementary Figure 8. (a) Specular XRD of FBR films as-cast and with annealing at
110 °C and 130 °C; (b) DSC first heating cycles measured at 5 °C min-1 on drop-cast samples
of FBR, P3HT and P3HT:FBR (1:1). Thermograms are offset vertically for clarity.
5 10 15 20 25 300
1
2
Inte
nsi
ty (
103 c
oun
ts)
2θ (degrees)
O-IDTBR as cast O-IDTBR annealed 110 °C O-IDTBR annealed 130 °C
5 10 15 20 25 300
1
2
Inte
nsit
y (1
03 cou
nts
)
2θ (degrees)
EH-IDTBR as cast EH-IDTBR annealed 110 °C EH-IDTBR annealed 130 °C
5 10 15 20 25 300
1
2
Inte
nsi
ty (1
03 co
unts
)
2θ (degrees)
FBR as cast FBR annealed 110 °C FBR annealed 130 °C
50 100 150 200 250
Hea
t Flo
w, E
ndo
Up
Temperature (°C )
FBR P3HT:FBR (1:1) P3HT
a b
Supplementary Figure 9. Chi-Q plots of (top) EH-IDTBR and EH-IDTBR:P3HT blend
(bottom) O-IDTBR and O-IDTBR:P3HT blend, for which the diffraction intensity is
integrated in two ranges of Chi = 87.5-92.5˚ and 40-50˚ and plotted against the whole wave
vector Q.
Supplementary Figure 10. Line cuts from GIXRD chi-Q plots of (a) EH-IDTBR and EH-
IDTBR:P3HT blend at 87.5-92.5°; (b) O-IDTBR and O-IDTBR:P3HT blend at 87.5-92.5°;
(c) O-IDTBR and O-IDTBR:P3HT blend at 40-50°.
EH-IDTBR EH-IDTBR:P3HT
O-IDTBR:P3HT O-IDTBR
0.4 0.6 0.8 1.0 1.2 1.4 1.6
104
105
106
107
Inte
nsity
(a.u
.)
Q (Å- 1)
O-IDTBR O-IDTBR:P3HT
87.5-92.5°
0.4 0.6 0.8 1.0 1.2 1.4 1.6
104
105
106
107
Inte
nsity
(a.u
.)
Q (Å-1)
O-IDTBR O-IDTBR:P3HT
40-50°
0.4 0.6 0.8 1.0 1.2 1.4 1.6
104
105
106
107
108
87.5-92.5°
Inte
nsi
ty (a
.u.)
Q (Å- 1)
EH-IDTBR EH-IDTBR:P3HT
a b c
Supplementary Figure 11. Current-voltage characteristics of electron-only devices of
different thickness in log-lin representation for (a) O-IDTBR:P3HT and (b) EH-
IDTBR:P3HT blends and of hole-only devices of different thickness for (c) EH-
IDTBR:P3HT blends. The solid lines represent fits to the experimental data (open triangles in
(a) and (b) and open dots in (c)) according to the Mott-Gurney law assuming space charge-
limited currents in these devices. Note that for EH-IDTBR:P3HT the hole mobility is about
two orders higher than the electron mobility.
c"
b"
-1 0 1 2 3 4 5 6
10-1
100
101
102
103
Cur
rent
Den
sity
(mA
cm
-2)
Voltage (V)
100 nm: 2.7x10-4 cm2V-1s-1
130 nm: 3.0x10-4 cm2V-1s-1
170 nm: 6.8x10-4 cm2V-1s-1
ITO/PEDOT:PSS/EH-IDTBR:P3HT/Au
0 1 2 3 410-5
10-4
10-3
10-2
10-1
100
101
102
Cur
rent
Den
sity
(mA
cm
-2)
Voltage (V)
190 nm: 6.1x10-6 cm 2V-1s-1
160 nm: 5.8x10-6 cm 2V-1s-1
130 nm: 3.2x10-6 cm 2V-1s-1
ITO/PEDOT:PSS/Al/EH-IDTBR:P3HT/Al
0 1 2 3 4
10-2
10-1
100
101
190 nm: 2.1x10-6 cm 2V-1s-1
160 nm: 4.7x10-6 cm 2V-1s-1
130 nm: 3.4x10-6 cm 2V-1s-1Cur
rent
Den
sity
(mA
cm
-2)
Voltage (V)
ITO/PEDOT:PSS/Al/O-IDTBR:P3HT/Al
a"
Supplementary Figure 12: Photoluminescence spectra of EH-IDTBR, O-IDTBR and
annealed EH-IDTBR:P3HT (130 °C for 10 min) and O-IDTBR:P3HT (130 °C for 20 min)
blends excited at 680 nm. Note that P3HT does not absorb at this excitation wavelength. All
the spectra are corrected for film absorption.
Supplementary Figure 13. Femtosecond-transient absorption spectra of (a), (b) EH-
IDTBR:P3HT and (c), (d) O-IDTBR:P3HT blends and pristine counterparts excited at 680
nm with 2µJ cm-2 density in N2 atmosphere at (a), (c) 1 pico-second (exciton signature) and
(b), (d) 6 nano-second (polaron signature).
700 725 750 775 8000
1x107
2x107
3x107
4x107
5x107
6x107P
hot
olu
min
esce
nce
(a.u
.)
Wavelength (nm)
P3HT EH-IDTBR EH-IDTBR:P3HT
750 800 850 900 950 1000 1050 11000.0
0.5
1.0
1.5
2.0
2.5
Ph
otol
umin
esce
nce
(a.u
.)
Wavelength (nm)
P3HT O-IDTBR O-IDTBR:P3HT
a" b"
Supplementary Figure 14. Oxidative stability of O-IDTBR:P3HT devices (normalised PCE
values) compared with other high performace polymer:fullerene systems (polymer structures
shown). Devices were exposed to air over the course of 1200 hr.
Supplementary Figure 15. Optical microscopy of O-IDTBR:P3HT blends in comparison
with PC60BM:P3HT blends. Films were prepared on ITO/ZnO coated glass substrates
according to procedures for the device active layers, and then annealed for 1 h under inert
atmosphere.
0 50 100150200 800 12000.00.10.20.30.40.50.60.70.80.91.01.11.2
PC60BM:P3HT (1:1) O-IDTBR:P3HT (1:1) PC70BM:PTB7 (1:1.5) PC70BM:PCE-10 (1:1.5) PC70BM:PCE-11 (1:1.4)
N
orm
alis
ed P
CE
time in air (hours)
S
S
O
O
S
SF
OO
n
PTB7 S
S
S
SF
OO
n
PCE-10
S
S
NS
N
F FS
S
S
S
C10H21 C8H17
C10H21C8H17
n
PCE-11
S
C6H13
nP3HT
Supplementary Table 1. Optoelectronic properties of PC60BM as measured in this study.
ε [104 M-1 cm-1]a) λmax film [nm] b) Eg opt. [eV]b) EA [eV] c) IP [eV] d)
0.39 (400 nm) 333 2.05 4.10 6.15
Measurements were carried out in a) CHCl3 solution; b) thin film spin-coated from 10 mg ml-1
chlorobenzene solution; c) cyclic voltammetry carried out on the as-cast thin film with 0.1 M
TBAPF6 electrolyte in acetonitrile; d) estimated from the EA and the optical Eg.
Supplementary Table 2. Photovoltaic characteristics of PC60BM:P3HT reference devices
Jsc [mA cm-2] Voc [V] FF PCE [%]
PC60BM:P3HT 9.59 0.58 0.67 3.73
Supplementary Table 3. Photovoltaic performance of O-IDTBR:P3HT OPV devices tested for differerent active areas under 100 mW cm-2 illumination.
Area of Device Jsc [mA/cm2] Voc [V] FF PCE [%] 0.045 cm2 14.1 0.73 0.62 6.4 0.15 cm2 13.9 0.72 0.63 6.3 0.75 cm2 11.9 0.73 0.55 4.8 1.5 cm2 11.1 0.73 0.53 4.3
Supplementary Table 4: Device parameters for the cells used in photo-CELIV measurements measured under 100 mW cm-2 illumination.
Jsc [mA cm-2] Voc [V] FF PCE [%]
O-IDTBR:P3HT 13.5 0.73 0.60 5.91
EH-IDTBR:P3HT 12.0 0.76 0.61 5.56