media.nature.com€¦ · web viewthe lateral au/perovskite/au structure without high-field poling...
TRANSCRIPT
Supplementary Information for
Quantification of light-enhanced ionic transport in
lead iodide perovskite thin films and its solar cell
applications
Yi-Cheng Zhao1, Wen-Ke Zhou1, Xu Zhou1, Kai-Hui Liu1,2*, Da-Peng Yu1,2, Qing
Zhao1,2*
1State Key Laboratory for Mesoscopic Physics and Electron Microscopy Laboratory,
School of Physics, Peking University, Beijing 100871, China.
2Collaborative Innovation Center of Quantum Matter, Beijing 100084, China.
*Correspondence to: [email protected]; [email protected]
1
5 mW cm-2
dark
t = 0 mina
b
c
20 mW cm-2
t = 2 min t = 4 min
Figure S1.Optical dynamic images of perovskite film under electric poling and
varied illumination intensity, in 10 Torr vacuum at room temperature. (a) The
film shows little change under dark at 100 V bias for 4 minutes (2 V m-1 high-field
poling). (b) The film shows black threads at the cathode, and moves toward anode in
4 minutes poling, under 5 mW cm-2 illumination with the same electric field.
Prolonged electrical poling for another 4 minutes under 5 mW cm -2 light intensity
cannot induce any further change. (c) Following the total 8 minutes’ poling under 5
mW cm-2, the film presents further destructed morphology near cathode after the 4
minutes poling under 20 mW cm-2 illumination. (Ionic motion almost stops after 4
minutes poling under 5 mW cm-2, but ions can move again to further change the
optical images with many black dots formed at the cathode under stronger
illumination. Note the gap size between the two gold electrodes is 50 m.)
2
10 15 20 25 30
0.0
0.5
1.0
1.5
2.0
In
tens
ity (N
orm
.)
2 theta (degrees)
#
Initial
After poling
(110) (220) Au Au
Si
Pb
IPb/I
Au Au Au
a b
c d
Initial
After poling After poling zoom-in
700 600 500 400 300 200 100 0
0.0
0.5
1.0
1.5
2.0
2.5Poling A
u
Initial
Si 2
p
Inte
nsity
(Nor
m.)
Binding energy (eV)
I 3d
O 1
s
Pb
4d
C 1
s
I 4s P
b 4f
I 4p
I 4d
Pb
5d
636 630 624 618 144 138 132
0.0
0.5
1.0
1.5
2.0
Inte
nsity
(Nor
m.)
Binding energy (eV)
I3d
Pb4f
e f
Figure S2. (a) X-ray diffraction patterns for Au/MAPbI3/Au lateral device on silica
substrate before and after high-field poling experiment, corresponding to the device in
Figure 1. ‘*’ denotes the poling-induced new phase PbI2 in the device, and ‘#’ denotes
the signals from silica substrate. The (110) (220) intensity from perovskite film
significantly decreased after electric poling, indicating the destructed perovskite
material in the device. (b) Distribution of Si, Pb, I and the corresponding Pb/I ratio for
3
the lateral Au/perovskite/Au structure without high-field poling on silica substrate,
through energy dispersive spectra. The gray arrow indicates the scan direction from
negative to the positive electrode. (c) Distribution of Si, Pb, I and the corresponding
Pb/I ratio for lateral structure after high-field poling in air under 1 V um-1 electric field
for 30 s. The scan area includes the dendrite structure. In that area, a signal of Pb and I
present sharp increase when a signal of silicon from the substrate shows a fast
decrease. (d) Zoom-in for the area includes dendrite structure. (e) X-ray photoelectron
spectra for perovskite with and without high-field poling. The global spectra for
destructed film present significant signal of Si(2p) and O(1s) from the substrate
below, indicating the formation of voids in the film with poling. (f) A closer look at Pb
4f and I 3d core levels show symmetric peaks. For I 3d, there is little shift in the
spectra. However, for Pb 4f, the orange line presents a larger full width at half
maximum (FWHM) compared to gray line without poling, which may be correlated
with the PbI2 formation in the poled sample, although both of them show a same
binding energy. It is hard to confirm whether reduction of Pb2+ occurs or not, because
both of them presents metallic Pb1.
4
5
3.5 4.0 4.5 5.0 5.5 6.0 6.5
0.0
0.2
0.4
0.6
0.8
1.0C
ount
s (N
orm
.)
Binding energy (eV)
PbAc2
0 200 400 600 800 1000
1
10
100
PL
inte
nsity
(a.u
.)
Time (ns)
=267.9 ns
a b
-1.0 -0.5 0.0 0.5 1.0-8
-4
0
4
8
Cur
rent
(mA
)
Bias voltage (V)
c
Figure S3. (a) Photoelectron energy spectroscopy (3.4-6.2 eV) for the prepared
MAPbI3 on TiO2/FTO substrate based on PbAc2/MAI precursor solution. It is
measured using a Photoelectron Spectrometer (Riken Keiki AC-2). The signal from
the conduction band is almost zero, implying that the Fermi level of our sample is
located around the valence band. (b) Time-resolved photoluminescence spectra for
MAPbI3 film on silica substrate prepared from PbAc2/MAI precursor solution. (c) The
current-voltage curves for ITO/PEDOT:PSS/Perovskite/Au structure, with an non-
rectifying behavior over the range of 2 V with a large current value, which indicates
the p type character of our sample.
6
15 20 25 30 35-1
0
1
2
3
4
5
(211)
120 K
150 K
190 K
215 K
(220)Inte
nsity
(Nor
m.)
2 theta (degree)
(202) (213)(110)
245 K
150 200 250 300 3500.00
0.03
0.06
0.09
0.12
0.15
Rel
ativ
e in
tens
ity (%
)
Temperature (K)
(211) facet (202) facet
Ttrans=190 K
a b
Figure S4 (a) X-ray diffraction patterns for MAPbI3 under different temperatures
from 120 to 245 K. (b) The relative intensity of the peak values for (211), (202) facets
as a function of temperature. The phase transition from orthorhombic to tetragonal
can be indicated by the abnormal increase for the intensities of (211), (202) facets
around 190 K.
7
a b
0 20 40 60 80 1000.0
0.5
1.0
1.5
2.0
Cou
nts
Sputtering time (s)
Pb/I Pb I
0 20 40 60 80 1000.0
0.5
1.0
1.5
2.0C
ount
s
Sputtering time (s)
Pb/I Pb I
Figure S5. (a) Ionic counts versus sputtering time for Pb+, I+, and the ratio Pb/I is
presented for the film without residual PbI2 and (b) with residual PbI2. The gray area
marks the bottom of the film with sharp drop of the counts at ~50 s. Although Pb/I
ratio increases in both cases due to different adhesive property to the substrate, the
film with PbI2 shows a larger value than that without PbI2. Since Pb/I ratio in PbI2 is
0.5 that is larger than in MAPbI3, we attribute the greater increase of Pb/I ratio in b, to
the residual PbI2 at the bottom of perovskite film.
Web Enhanced Objects. Supplementary Movie 1-3. Real time optical image recording
of the lateral structure Au/MAPbI3/Au under 2V m-1 electric poling under 0 mW cm-2
(Movie 1), 5 mW cm-2 (Movie 2), 20 mW cm-2 (Movie 3).
1 Lindblad R, Bi D, Park BW, Oscarsson J, Gorgoi M, Siegbahn H, et al. Electronic Structure of TiO2/CH3NH3PbI3 Perovskite Solar Cell Interfaces. J Phys Chem Lett. 2014;5:648-53.
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