Supplementary information for
Highly efficient hybrid warm white organic light-emitting diodes using a blue thermally
activated delayed fluorescence emitter: exploiting the external heavy-atom effect
Dongdong Zhang, Lian Duan*, Yunge Zhang, Minghan Cai, Deqiang Zhang, Yong Qiu
Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education,
Department of Chemistry, Tsinghua University, Beijing 100084, China.
*Correspondence to: E-mail address: duanl@mail.tsinghua.edu.cn.Fax: +86 10 62795137;
Tel: +86 10 62782197
1. The influence of EHA on emission process.
Figure S1. The influence of EHA on the conventional fluorescence process (a) and the TADF
process (b).
2. The absorption spectrum of mCP film.
1.0
mCP
Intensity (a.u.)
0.8
0.6
0.4
0.2
430 nm
490 nm
0.0
200
300
400
500
Wavelength (nm)
Figure S2. The absorption spectrum of pure mCP film.
3. The PL behavior of fluorophors under the influence of EHA perturbers.
1
0.45
2.5
a
0.40
0.45
mCP: Alq3: Ir(ppz)3
mCP: Alq3: Pt(COD)Cl2
1.5
mCP: Alq3: Pt(COD)Cl2
0.35
0.30
0.30
1.0
0.15
0.5
0.10
1.0
0.25
F0/F-1
0.20
PL efficiency
1.5
0.25
F0/F-1
PL efficiency
b
0.40
2.0
mCP: Alq3: Ir(ppz)3
0.35
0.20
0.15
0.5
0.10
0.05
0.05
0.0
0.0
0.00
10
5
0
0.00
30
25
20
15
0
5
Concentration of phosphors (wt%)
10
15
20
25
30
Concentration of phosphors (wt%)
Figure S3. a) The PL efficiency and the Stern-Volmer plot for mCP: 5% Alq3: Ir(ppz)3. b)
The PL efficiency and the Stern-Volmer plot for mCP: 5% Alq3: Pt(COD)Cl2.
1.0
a
0
5
10
15
20
25
30
mCP: 5 wt% t-Bu4CzTPN-Firpic
0.8
0
5
10
15
20
25
30
0.6
Intensity (a.u.)
Intensity (a.u.)
0.9
b
mCP: 5 wt% t-Bu4CzTPN: Pt (COD)Cl2
0.6
0.4
0.3
0.2
500
550
600
650
700
550
750
600
650
700
750
Wavelength (nm)
Wavelength (nm)
1.0
c
0.8
Intensity (a.u.)
d
0
5
10
15
20
25
30
mCP: 5 wt% Bebq2: Pt(COD)Cl2
0.6
0
5
10
15
20
25
30
mCP: 5 wt% Bebq2: Ir(ppz)3
0.8
Intensity (a.u.)
1.0
0.4
0.6
0.4
0.2
0.2
0.0
500
550
600
650
700
450
750
500
1.0
1.0
e
0
5
10
15
20
25
30
mCP: 5 wt% Alq3: Ir(ppz)3
0.6
600
f
650
700
0
5
10
15
20
25
30
mCP: 5% Alq3: Pt(COD)Cl2
0.8
Intensity (a.u.)
Intensity (a.u.)
0.8
550
Wavelength (nm)
Wavelength (nm)
0.4
0.6
0.4
0.2
0.2
0.0
0.0
500
550
600
650
700
500
750
Wavelength (nm)
550
600
650
700
750
Wavelength (nm)
Figure S4. a) The spectra of the films of mCP: 5% t-Bu4CzTPN: Pt(COD)Cl2. b) The spectra
of the films of mCP: 5% t-Bu4CzTPN: Firpic. c) The spectra of the films of mCP: 5% Bebq2:
2
Pt(COD)Cl2. d) The spectra of the films of mCP: 5% Bebq2: Ir(ppz)3. e) The spectra of the
films of mCP: 5% Alq3: Ir(ppz)3. f) The spectra of the films of mCP: 5% Alq3: Pt(COD)Cl2.
4. The PL transient decay curves of the fluorophors.
10000
0
5
10
15
20
25
mCP: t-Bu4CzTPN: Pt(COD)Cl2
Counts
1000
100
b
1000
Counts
a
100
10
10
1
1
2500
5000
7500
10000
12500
20
15000
40
60
0
5
10
15
20
25
30
mCP: Alq3: Ir(ppz)3
100
100
10
0
5
10
15
20
25
30
mCP: Alq3: Pt(COD)Cl2
d
1000
Counts
c
1000
80
Time (ns)
Time (ns)
Counts
0
5
10
15
20
25
mCP: Bebq2: Pt(COD)Cl2
100
10
1
1
50
100
150
200
250
100
150
200
Time (ns)
250
300
350
Time (ns)
3.00E+008
e
kISC+knr
kr
2.00E+008
kr
Bebq2
-1
-1
Rate constant (s )
f
kISC+knr
Rate constant(s )
2.50E+008
1.50E+008
1.00E+008
Alq3
5.00E+007
5.00E+007
0
5
10
15
20
0
Concentration of perturbers (wt%)
5
10
15
20
Concentration of perturbers (wt%)
80000000
70000000
g
-1
Rate constant (s )
60000000
50000000
40000000
kISC+knr
30000000
kr
20000000
t-Bu4CzTPN
10000000
0
5
10
15
20
Concentration of perturbers (wt%)
Figure S5. a) The transient decay curves of films of mCP: t-Bu4CzTPN: Pt(COD)Cl2
observed at 570 nm with excitation wavelength of 430 nm. b) The transient decay curves of
films of mCP: Bebq2: Pt(COD)Cl2 observed at 490 nm with excitation wavelength of 430 nm.
3
c) The transient decay curves of films of mCP: Alq3: Ir(ppz)3 observed at 520 nm with
excitation wavelength of 430 nm. d) The transient decay curves of films of mCP: Alq3:
Pt(COD)Cl2 observed at 520 nm with excitation wavelength of 430 nm. e) The rate constant
of Bebq2 under the influence of Ir(ppz)3. f) The rate constant of Alq3 under the influence of
Ir(ppz)3. g) The rate constant of t-Bu4CzTPN under the influence of Firpic.
1000
Counts
100
10
100
200
Time (ns)
300
400
Figure S6. The transient decay curves of t-Bu4CzTPN: Firpic in dichloromethane solution
without degassing. The concentration of Firpic is gradually increased. The excitation
wavelength is 490 nm while the observed wavelength is 570 nm.
Table S1: Transient characteristics of the films.
Films
τ (ns)
kS1 (s-1)
Increase of kISC
8
mCP: Bebq2: 0% Ir(ppz)3
5.8
1.72×10
mCP: Bebq2: 5% Ir(ppz)3
4.5
2.22×108
0.5×108
mCP: Bebq2: 10% Ir(ppz)3
4.1
2.44×108
0.72×108
8
mCP: Bebq2: 15% Ir(ppz)3
3.5
2.86×10
1.14×108
mCP: Bebq2: 20% Ir(ppz)3
3.0
3.33×108
1.61×108
7
mCP: Alq3: 0% Ir(ppz)3
24.0
4.17×10
mCP: Alq3: 5% Ir(ppz)3
21.0
4.76×107
0.59×107
mCP: Alq3: 10% Ir(ppz)3
18.5
5.41×107
1.24×107
7
mCP: Alq3: 15% Ir(ppz)3
16.5
6.06×10
1.89×107
mCP: Alq3: 20% Ir(ppz)3
14.2
7.04×107
2.87×107
7
mCP: t-Bu4CzTPN: Firpic
17.0
5.88×10
t-Bu4CzTPN: Firpic in dichloromethane
10.0
1.00×108
Note: 1) The lifetime of mCP: t-Bu4CzTPN: Pt(COD)Cl2 are the lifetime of the prompt part
of the decay curves.
2) The kS1 here stands for the rate of all the process of the singlet excitons.
3) The increase of kISC is the D-value of kS1 with or without EHA perturbers.
4) The fitting equation for the life-times of the PL decay curves of films is like below:
Fit  A  B1  e( t /1 )  B2  e( t / 2 )  B3  e ( t / 3 ) .
Where τ1 is the life-time of the prompt part of the photo decay curve, τ2 and τ3 is the
life-time of the delayed part of the photo decay curve.
5. The PL characteristics of mCP: 2CzPN: PO-01 films.
4
0.90
0.90
a
PL efficiency
PL efficiency
b
0.85
0.85
0.80
mCP: PO-01
0.75
0.80
0.75
0.70
0.70
0.65
0.65
0.2
0.4
0.6
0.8
mCP: 10% 2CzTPN: PO-01
0.0
1.0
0.2
0.4
0.6
0.8
1.0
Concentration of PO-01 (wt%)
Concentration of PO-01 (wt%)
1200
1000
c
mCP: 10% 2CzPN
mCP: 10% 2CzPN: 0.4% PO-01
mCP: 0.4% PO-01
1200
800
1000
Intensity
B
d
1400
mCP: 10% 2CzPN
mCP: 10% 2CzPN: 0.2% PO-01
mCP: 0.2% PO-01
600
800
600
400
400
200
200
0
0
450
500
550
600
650
700
750
800
450
500
1800
1600
1800
mCP: 10% 2CzPN
mCP: 10% 2CzPN: 0.6% PO-01
mCP: 0.6% PO-01
e
1400
700
750
800
mCP: 10% 2CzPN
mCP: 10% 2CzPN: 0.8% PO-01
mCP: 0.8% PO-01
Intensity
1200
1000
800
800
600
600
400
400
200
200
0
0
450
500
550
600
650
700
750
450
800
500
g
550
600
650
700
750
800
Wavelength (nm)
Wavelength (nm)
1800
650
1400
1000
2000
600
f
1600
1200
Intensity
550
Wavelength (nm)
A
mCP: 10% 2CzPN
mCP: 10% 2CzPN: 1 % PO-01
mCP: 1% PO-01
0.90
1600
h
0.85
PL efficiency
Intensity
1400
1200
1000
800
600
0.80
0.75
calculated
0.70
400
200
0.65
0
450
500
550
600
650
700
750
800
0.2
0.4
0.6
0.8
1.0
Concentration of PO-01 (wt%)
Wavelength (nm)
Figure S7. a) The PL efficiencies of mCP: PO-01 films. b) The PL efficiencies of mCP:
2CzPN: PO-01 films. c) The PL spectrum of mCP: 5% 2CzPN: 0.2% PO-01 film and the
separated spectra of 2CzPN and PO-01. d) The PL spectrum of mCP: 5% 2CzPN: 0.4%
PO-01 film and the separated spectra of 2CzPN and PO-01. e) The PL spectrum of mCP: 5%
2CzPN: 0.6% PO-01 film and the separated spectra of 2CzPN and PO-01. f) The PL spectrum
5
of mCP: 5% 2CzPN: 0.8% PO-01 film and the separated spectra of 2CzPN and PO-01. g) The
PL spectrum of mCP: 5% 2CzPN: 1.0% PO-01 film and the separated spectra of 2CzPN and
PO-01. h) The calculated PL efficiencies of mCP: 2CzPN: PO-01 films. .
6. The PL characteristics of mCP: Bebq2: PO-01 films.
250000
mCP: 10% Bebq2: 0.2% PO-01
a
200000
mCP: 0.2% PO-01
mCP: 10% Bebq2: 0.4% PO-01
b
mCP: 10% Bebq2
200000
mCP: 10% Bebq2
mCP: 0.4% PO-01
150000
Intensity
Intensity
150000
100000
100000
50000
50000
0
0
400
450
500
550
600
650
700
750
400
Wavelength (nm)
500
550
600
650
700
750
800
Wavelength (nm)
300000
300000
mCP: 10% Bebq2: 0.8% PO-01
mCP: 10% Bebq2: 0.6% PO-01
c
250000
mCP: 10% Bebq2
mCP: 10% Bebq2
d
250000
mCP: 0.6% PO-01
mCP: 0.8% PO-01
200000
Intensity
200000
Intensity
450
150000
150000
100000
100000
50000
50000
0
0
400
500
600
700
400
800
500
600
700
800
Wavelength (nm)
Wavelength (nm)
300000
mCP: 10% Bebq2: 1.0% PO-01
e
250000
0.9
mCP: 10% Bebq2
f
mCP: 1.0% PO-01
0.8
PL efficiency
Intensity
200000
150000
100000
0.7
0.6
mCP: PO-01
mCP: Bebq2: PO-01 measured
mCP: Bebq2: PO-01 calculated
0.5
50000
0.4
0
400
450
500
550
600
650
700
750
800
0.0
0.2
Wavelength (nm)
0.4
0.6
0.8
1.0
Concentration of PO-01
Figure S8. a) The PL spectrum of mCP: 5% Bebq2: 0.2% PO-01 film and the separated
spectra of 2CzPN and PO-01. b) The PL spectrum of mCP: 5% Bebq2: 0.4% PO-01 film and
the separated spectra of 2CzPN and PO-01. c) The PL spectrum of mCP: 5% Bebq2: 0.6%
PO-01 film and the separated spectra of 2CzPN and PO-01. d) The PL spectrum of mCP: 5%
Bebq2: 0.8% PO-01 film and the separated spectra of 2CzPN and PO-01. e) The PL spectrum
of mCP: 5% Bebq2: 1.0% PO-01 film and the separated spectra of 2CzPN and PO-01. f) The
PL efficiencies of films.
Table S2. The PL efficiencies of films.
Ratio
Films
2CzPN
of Ratio
PO-01
of
calculated
experimental
mCP: 5%2CzPN: 0.2% PO-01
0.364
0.636
0.730
0.764
mCP: 5%2CzPN: 0.4% PO-01
0.295
0.705
0.775
0.803
6
mCP: 5%2CzPN: 0.6% PO-01
0.165
0.835
0.827
0.842
mCP: 5%2CzPN: 0.8% PO-01
0.144
0.856
0.850
0.854
mCP: 5%2CzPN: 1.0% PO-01
0.098
0.902
0.881
0.89
mCP: 0.2% PO-01
1.0
0.77
mCP: 0.4% PO-01
1.0
0.816
mCP: 0.6% PO-01
1.0
0.86
mCP: 0.8% PO-01
1.0
0.882
mCP: 1.0% PO-01
1.0
0.904
mCP: 5% 2CzPN
1.0
Note: the ratio of 2CzPN or PO-01 is the ratio of the photon.
0.66
Table S3. The energies of the compounds.
singlet (eV)
Triplet (eV)
Alq3
2.4
2.0
Bebq2
2.52
2.26
t-Bu4CzTPN 2.24
2.17
2CzPN
2.6
2.5
HOMO (eV)
5.6
5.5
5.8
LUMO (eV)
2.8
2.8
3.0
Pt(COD)Cl2
-
>3.0
-
-
Ir(ppz)3
-
3.0
5.0
1.6
Firpic
-
2.62
5.9
2.85
PO-01
-
2.2
5.1
2.7
7. The performances of the WOLEDs.
b
a
100
2
Brightness (cd/m )
2
Current density (A/m )
1000
100
A: 6% 2CzPN: 0.2% PO-01
B: 10% 2CzPN: 0.2% PO-01
C: 20% 2CzPN: 0.2% PO-01
10
10
A: 6% 2CzPN: 0.2% PO-01
B: 10% 2CzPN: 0.2% PO-01
C: 20% 2CzPN: 0.2% PO-01
1
0.1
1
4
5
6
7
8
9
4
10
Voltage (V)
5
6
7
Voltage (V)
7
8
9
10
c
Intensity (a.u.)
0.8
0.6
4V
5V
6V
7V
8V
9V
10 V
10% 2CzPN
d
1.0
4V
5V
6V
7V
8V
9V
10 V
6% 2CzPN
0.8
Intensity (a.u.)
1.0
0.4
0.6
0.4
0.2
0.2
0.0
0.0
400
500
600
400
700
Wavelength (nm)
500
600
700
Wavelength (nm)
1.0
4V
5V
6V
7V
8V
9V
10 V
20% 2CzPN
Intensity (a.u.)
0.8
0.6
4V
5V
6V
7V
8V
9V
10 V
A: 6% 2CzPN
f
0.8
0.6
CIE y
e
1.0
0.4
0.4
0.2
0.2
0.0
0.0
400
500
600
700
Wavelength (nm)
1.0
CIE y
0.6
0.4
0.8
CIE y
0.8
0.2
0.4
CIE x
1.0
4V
5V
6V
7V
8V
9V
10 V
B: 10% 2CzPN
g
0.0
0.2
0.6
0.8
1.0
4V
5V
6V
7V
8V
9V
10 V
C: 20% 2CzPN
h
0.6
0.4
0.2
0.0
0.0
0.2
0.4
CIE x
0.6
0.8
0.0
0.0
1.0
0.3
CIE x
0.6
0.9
Figure S9. a) Brightness-voltage characteristics and b) current density-voltage characteristics
of the WOLEDs. c) The spectra of device A. d) The spectra of device B. e) The spectra of
device C. f) The CIE coordinates spectra of device A. g) The CIE coordinates spectra of
device B. h) The CIE coordinates spectra of device C.
8. The performance of monochromatic devices
mCP: 20% 2CzPN: 0.2% PO-01
mCP: 20% 2CzPN
mCP: 0.2% PO-01
EQE
20
10
0
0
2000
4000
6000
8000
2
Brightness (cd/m )
8
Figure S10. The performance of monochromatic devices of 2CzPN or PO-01 in the same
device architecture. ITO/ HATCN (5 nm)/ NPB (40 nm)/ TCTA (10 nm)/ mCP: 20% 2CzPN
or mCP: 0.2% PO-01(11 nm) / TAZ (40 nm)/ LiF (0.5 nm) /Al (150 nm).
9. The performance of WOLEDs with 26DCzPPy as the host.
b
Power efficiency (lm/W)
Current Efficiency (cd/A)
a
10
26DCzPPy: 20% 2CzPN: 0.2% PO-01
1
10
1
10
100
1.0
2
Brightness (cd/m )
1000
0
1000
2000
3000
2
4000
5000
6000
Brightness (cd/m )
4V
5V
6V
7V
8V
c
0.8
Intensity (a.u.)
26DCzPPy: 20% 2CzPN: 0.2% PO-01
0.6
0.4
0.2
0.0
400
500
600
700
Wavelength (nm)
Figure S11. a) The Current efficiency-brightness characteristics of the WOLED. b) The power
efficiency-brightness characteristics of the WOLED. c) The spectra of the WOLED with
increasing voltage. The device structure is ITO/ HATCN (5 nm)/ NPB (40 nm)/ TCTA (10
nm)/ 26DCzPPy: 20% 2CzPN: 0.2% PO-01(11 nm) / TAZ (40 nm)/ LiF (0.5 nm) /Al (150
nm).
10. The lifetime of devices.
110
100
a
100
b
mCP: 20% 2CzPN: 0.5% PO-01
mCP: 20% 2CzPN
mCP: 0.5% PO-01
90
80
80
B
I/I0 (%)
60
70
26DCzPPy: 20% 2CzPN: 0.2% PO-01
mCP: 20% 2CzPN: 0.2% PO-01
40
60
20
50
40
0
20
40
60
80
100
120
0
140
Time (min)
0
100
200
Time (min)
300
400
500
Figure S12. a) The lifetimes of devices with mCP as the host. b) The lifetimes of WOLEDs
with mCP or 26DCzPPy as the host.
9