Supporting Information
Highly stable and efficient solid state solar cells based on methylammonium lead bromide
(CH3NH3PbBr3) perovskite quantum dots
Sawanta S. Mali Chang Su Shim, Chang Kook Hong*
*Polymer Energy Materials Laboratory, School of Applied Chemical Engineering, Chonnam
National University, Gwangju, 500-757 (South Korea),
S1 Characterizations
The surface morphology of the prepared samples was recorded by a field emission
scanning electron microscope (FESEM; S-4700, Hitachi). Transmission electron microscopy
(TEM) micrographs, selected area electron diffraction (SAED) pattern and high-resolution
transmission electron microscopy (HRTEM) images were obtained by TECNAI F20 Philips
operated at 200 KV. The TEM sample was prepared by drop casting of ethanolic dispersion
of the sample onto a carbon coated Cu grid. X-ray diffraction (XRD) measurements were
carried out using a D/MAX Uitima IIIXRD spectrometer (Rigaku, Japan) with CuK line of
1.5410 Å. The elemental information regarding the deposited samples was analyzed using
an STEM and EDS analysis which is connected with TEM.
The cells were illuminated using a solar simulator at AM 1.5 G for 10 s, where the
light intensity was adjusted with an NREL-calibrated Si solar cell with a KG-5 filter to 1 sun
intensity (100 mW cm-2). The IPCE spectra were measured as a function of wavelength
from 300 to 1100 nm on the basis of a Spectral Products DK240 monochromator.
Photoluminescence measurements were carried out on a PL mapper (Accent Opt. Tech. UK,
Model:RPM 2000, 532nm ND-YAG laser excitation).
Figure S1 Plane view of STEM micrographs of CH3NH3PbBr3 decorated mp-TiO2 and EDS
mapping of each elements. The elements are mentioned as per respective colors. Carbongreen, titanium-red, oxygen-cyan, lead-yellow, bromine-cyan.
Figure S2 TEM analysis of CH3NH3PbBr3+mp-TiO2 composite having ~10nm CH3NH3PbBr3
particle size (a) TEM micrograph of the perovskite CH3NH3PbBr3 deposited on mp-TiO2
nanoparticles (b-c) Highly magnified TEM images of CH3NH3PbBr3 coated TiO2
nanoparticles at different magnification. (d) HRTEM image of CH3NH3PbBr3 +mpTiO2.
Figure S3 TEM analysis of CH3NH3PbBr3+mp-TiO2 composite having ~7-6nm particle
size (a) TEM micrograph of the perovskite CH3NH3PbBr3 deposited on mp-TiO2
nanoparticles (b-c) Highly magnified TEM images of CH3NH3PbBr3 coated TiO2
nanoparticles at different magnification. Inset shows FFT analysis of single CH 3NH3PbBr3
nanoparticle (d) HRTEM image of CH3NH3PbBr3 +mpTiO2.
Figure S4
TEM analysis of
CH3NH3PbBr3+mp-TiO2
composite having ~5-4nm
CH3NH3PbBr3 particle size (a) TEM micrograph of the perovskite CH 3NH3PbBr3 deposited
on mp-TiO2 nanoparticles (b-c) Highly magnified TEM images of CH3NH3PbBr3 coated TiO2
nanoparticles at different magnification. (d) HRTEM image of CH3NH3PbBr3 +mpTiO2.
Figure S5 Normalized photoluminescence spectra of MAPbBr3 nanoparticles/quantum
dots with different size.
MAPbBr3 (~10nm)
MAPbBr3 (~7nm)
MAPbBr3 (~5nm)
Normalized PL
MAPbBr3 (~3nm)
550
600
Wavelength (nm)
650
700
Figure S6 J-V curves of forward and reverse bias sweep and respective JV curves for spiroMeOTAD using CH3NH3PbBr3 perovskite absorber layer with different size. J-V curves
measured by forward and reverse scans with 10mV voltage steps and 50ms delay times
under AM 1.5 G illumination.
12
10nm Forwad
10nm Reversed
7nm Forward
7nm Reversed
5nm Forward
5nm Reversed
-2
Current density (mA.cm )
10
8
6
4
2
FTO/Bl-TiO2/mp-TiO2+MAPbBr3/spiro-MeOTAD/Au
0
0.0
0.2
0.4
0.6
Voltage (V)
0.8
1.0
Figure S7 J-V curves of forward and reverse bias sweep and respective JV curves for PTAA
using CH3NH3PbBr3 perovskite absorber layer with different size. J-V curves measured by
forward and reverse scans with 10mV voltage steps and 50ms delay times under AM 1.5 G
illumination.
Current density (mAcm-2)
12
10nm Forward
10 reversed
7nm Forward
7nm Reversed
5 nm Forward
5nm Revesred
10
8
6
4
2
FTO/Bl-TiO2/mp-TiO2+MAPbBr3/PTAA/Au
0
0.0
0.2
0.4
0.6
0.8
Voltage (V)
1.0
1.2
Figure S8 Cross-sectional field emission scanning electron microscopic images of FTO/BlTiO2/mp-TiO2+MAPbBr3/HTM/Au. (a-d) cross sectional images of PTAA based devices (e-f)
spiro-MeOTAD based perovskite devices. The mp-TiO2 layer has been deposited at different
spin coating speed. (a) 2500, (b) 3000, (c) 4000, (d) 5000, (e) 3000 (f) 4000rpm. Figure (e)
(e) and (f) show spiro-MeOTAD HTM based devices. Figure (e) shows ~80nm Au contact.
Figure S9 Average solar cell efficiencies were obtained from different MAPbBr3
nanoparticles/quantum dots with different HTM materials.
8
10
spiro-MeOTAD
PTAA
9
8
6
7
5
6
5
4
4
3
2
4
6
MAPbBr3 size (nm)
8
10
Efficiency for PTAA
Efficiency for spiro-MeOTAD
7
Table S1: Solar cell properties of MAPbBr3 based perovskite solar cells having different
size. Device configuration FTO/Bl-TiO2/mp-TiO2/CH3NH3PbBr3/spiro-MeOTAD/Au
HTM
SpiroMeOTAD
SpiroMeOTAD
SpiroMeOTAD
Particle
Scan
size
direction
~10nm
~7-8nm
~5-7nm
VOC
(V)
JSC
(mAcm-2)
FF

()
Average

Forward
0.839
8.37
0.43
3.02
3.47
Reverse
0.888
8.15
0.54
3.91
Forward
0.904
9.11
0.49
4.04
Reverse
0.873
8.97
0.54
4.22
Forward
0.862
10.06
0.46
4.45
Reverse
0.894
9.79
0.52
4.55
4.13
4.5
Table S2: Solar cell properties of MAPbBr3 based perovskite solar cells having different
size. Device configuration FTO/Bl-TiO2/mp-TiO2/CH3NH3PbBr3/PTAA/Au
HTM
PTAA
PTAA
PTAA
Particle
Scan
size
direction
~10nm
~7-8nm
~5-7nm
VOC
(V)
JSC
(mAcm-2)
FF

()
Average

Forward
1.071
8.10
0.42
3.64
4.02
Reverse
1.069
8.41
0.49
4.40
Forward
1.043
09.21
0.52
4.99
Reverse
1.047
09.44
0.58
5.73
Forward
1.032
10.62
0.53
5.81
Reverse
1.082
10.85
0.59
6.93
5.36
6.73