Subscriber access provided by UNIV OF LOUISIANA
Article
High-Performance Fused Ring Electron Acceptor-Perovskite Hybrid Mingyu Zhang, Shuixing Dai, Sreelakshmi Chandrabose, Kai Chen, Kuan Liu, Minchao Qin, Xinhui Lu, Justin M Hodgkiss, Huanping Zhou, and Xiaowei Zhan J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.8b09300 • Publication Date (Web): 15 Oct 2018 Downloaded from http://pubs.acs.org on October 15, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
High-Performance Fused Ring Electron Acceptor-Perovskite Hybrid
2
Mingyu Zhang,† Shuixing Dai,† Sreelakshmi Chandrabose,‡ Kai Chen,‡ Kuan Liu,† Minchao Qin,§
3
Xinhui Lu,§ Justin M. Hodgkiss, ‡ Huanping Zhou,*,† and Xiaowei Zhan*,†
4 5
†Department
6
Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, China
7
‡MacDiarmid
8
Physical Sciences, Victoria University of Wellington, Wellington 6010, New Zealand
9
§Department
10
of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer
Institute for Advanced Materials and Nanotechnology and School of Chemical and
of Physics, The Chinese University of Hong Kong, New Territories 999077, Hong Kong,
China
1 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 2 of 27
1
Abstract
2
We report fused ring electron acceptor (FREA)-perovskite hybrid as a promising platform to fabricate
3
organic-inorganic hybrid solar cells with simple preparation, high efficiency and good stability. The
4
FREA-perovskite hybrid films exhibit larger grain sizes and stronger crystallinity than the pristine
5
perovskite
6
under-coordinated Pb atoms and passivate the trap states in the perovskite films. Time-resolved
7
photoluminescence and transient absorption measurements reveal that FREA facilitates efficient electron
8
extraction and collection. Transient photocurrent and photovoltage measurements suggest faster charge
9
transfer and reduced charge recombination in solar cells based on FREA-perovskite hybrid films.
10
Consequently, solar cells based on FREA-perovskite hybrid films yield a champion efficiency of 21.7%
11
with enhanced stability, which is higher than that of the control devices based on pristine perovskite
12
films (19.6%).
films.
Moreover,
the
FREA
molecules
can
2 ACS Paragon Plus Environment
form
coordination
bonding
with
Page 3 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
Introduction
2
Since the organic-inorganic hybrid perovskite was first used as a light-absorbing material in solar cells
3
in 2009,1 power conversion efficiency (PCE) of perovskite solar cells (PSCs) has achieved an
4
astonishingly rapid increase from 3.8% to over 22%.2-7 The high-quality absorbing layer plays the most
5
important role in the high-performance PSCs. Since pinholes, grain boundaries, crystal defects and trap
6
states in perovskite films would induce nonradiative charge recombination, reduce carrier lifetime and
7
decrease device performance, larger grain sizes, stronger crystallinity and less defects of perovskite
8
films are desired.8-14 Numerous strategies, such as solvent selection for perovskite precursor, thermal
9
annealing, solvent annealing and additive engineering, have been used to improve perovskite film
10
quality.15-20 In particular, various additives, such as hydroiodic acid (HI),21-22 ionic liquid,23 Lewis
11
base,18,
12
derivatives,11-12, 36-39 were incorporated into precursor solution to manipulate the nucleation and growth
13
process of perovskite films, and passivate the trap states caused by under-coordinated Pb2+.
24-25
alkali metal cations (e.g. Li+, Na+, K+, Al3+),26-28 polymers,10,
29-35
and fullerene
14
n-Type organic semiconductors have been widely used as electron-transporting layer and interfacial
15
modifying layer in PSCs since they have diverse functional groups with lone pair electrons that can
16
effectively passivate the trap states of the perovskite film, and high electron affinity and electron
17
mobility that can promote the electron extraction and electron transport.40-44 However, only couple
18
works used n-type organic semiconductors as additives in perovskite films to realize grain boundary
19
passivation45 or long-term stability of the perovskite precursor solution,46 leading to PCEs of ca. 19%.
3 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 4 of 27
1
Recently, we proposed the concept of fused ring electron acceptor (FREA), which consists of strong
2
electron-donating planar fused ring core flanked with two strong electron-accepting terminal groups, and
3
now the FREA is emerging as a class of the best-performing nonfullerene acceptors in organic solar
4
cells
5
6,6,12,12-tetrakis(4-hexylphenyl)-indacenobis(dithieno[3,2-b;2',3'-d]thiophene)
6
3-(1,1-dicyanomethylene)-5/6-fluoro-1-indanone terminal groups, and exhibits strong absorption in
7
visible and near-infrared region, high electron mobility and high efficiency in OSCs.50
(OSCs).47-52
For
example,
INIC2
is
a
FREA
molecule
based
end-capped
on by
8
In this work, we fabricated FREA-perovskite hybrid films for organic-inorganic hybrid solar cells
9
with high efficiency and good stability. We chose INIC2 based on the following considerations. First,
10
the fluorinated electron-withdrawing end-groups promote the compatibility of INIC2 and DMF solvent.
11
The existence of INIC2 facilitates the nucleation of PbI2, thus controls the morphology of the perovskite
12
films. Therefore, we obtained the optimal perovskite films with larger grain sizes and stronger
13
crystallinity. Second, the INIC2 molecule owns lone pair electrons, which can passivate the defects
14
caused by under-coordinated Pb atoms and reduce charge recombination. Third, INIC2 promotes
15
efficient charge transport in PSCs due to suitable energy levels and high mobility. Benefited from the
16
above advantages, the planar heterojunction PSCs based on INIC2-perovskite hybrid films (Figure 1)
17
achieved a champion PCE of 21.7%, which was higher than that of the control devices without INIC2
18
(19.6%). Moreover, the ambient stability of the devices based on INIC2-perovskite hybrid films were
19
dramatically enhanced relative to the devices based on pristine perovskite films.
20
Results and Discussion 4 ACS Paragon Plus Environment
Page 5 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
Morphology. FREA-perovskite hybrid films were prepared using simple method, and the details see
2
Supporting Information. The energy dispersive X-ray spectrometric microanalysis (EDX) of Pb and F
3
elements in PbI2:INIC2 and perovskite:INIC2 films (Figure S1) indicates that both elements show
4
excellent homogeneity and dispersivity, suggesting that INIC2 has good compatibility in the PbI2
5
solution and perovskite film. The top-view scanning electron microscopy (SEM) images of PbI2 films
6
without and with INIC2 are shown in Figure S2. More and smaller PbI2 grains with INIC2 were
7
observed, indicating more nucleation sites and lower nucleation free energy of PbI2. The top-view SEM
8
images of perovskite films (Figure S2) exhibit that the grain size of perovskite films is affected by
9
INIC2 concentration. The grain size of perovskite film increases with increasing INIC2 concentration
10
from 0 to 0.3 mg mL-1. However, the grain size of perovskite film decreases at INIC2 concentration of
11
0.5 mg mL-1. The addition of INIC2 into PbI2 solution provides heterogeneous nucleation sites to reduce
12
the nucleation free energy of PbI2, and facilitates PbI2 diffusion and reaction with organic cations,
13
leading to enlarged grain size of perovskite.
14
The crystal structures of PbI2 and perovskite films were studied by X-ray diffraction (XRD). The
15
main diffraction peak intensity of PbI2 decreases (Figure 2a), and its full width at half-maximum
16
(FWHM) increases (Figure S3a) with INIC2. The existence of INIC2 increases the nucleation sites of
17
PbI2, and reduces the energy barrier of nucleation, leading to a faster nucleation and decreased intensity
18
of main peak.53-54 The XRD patterns of the perovskite films (Figure 2b) have typical perovskite peaks at
19
13.98° and 28.2°, assigned to the (001) and (002) planes of cubic phase perovskite, respectively. No
20
impurity phases were observed in the INIC2-perovskite hybrid films. The INIC2-perovskite hybrid films 5 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 6 of 27
1
exhibit stronger intensity of (001) diffraction peak with a smaller FWHM (Figure S3b). The PbI2 grains
2
with weaker crystallinity have stronger reactivity with organic cations, leading to formation of
3
high-quality perovskite films with stronger diffraction peaks.55-56 The XRD patterns of perovskite films
4
with different INIC2 concentration are shown in Figure S3c. The intensity of (001) diffraction peak of
5
perovskite film is affected by INIC2 concentration. The intensity of (001) diffraction peak enhances
6
with increasing INIC2 concentration from 0 to 0.3 mg mL-1. However, the intensity of (001) diffraction
7
peak decreases at INIC2 concentration of 0.5 mg mL-1. These XRD results are consistent with the SEM
8
images.
9
To further investigate the effect of INIC2 on the crystallinity of perovskite films, grazing-incidence
10
wide-angle X-ray scattering (GIWAXS) measurements were performed. The two-dimensional GIWAXS
11
patterns of the perovskite films without and with INIC2 are shown in Figure 2c and d. No diffraction
12
peaks from INIC2 can be identified due to the tiny amount added and the relatively strong crystallinity
13
of perovskites. Both GIWAXS patterns exhibit a strong (001) peak at q = 1 Å−1. The diffraction peak of
14
PbI2 is greatly suppressed after incorporating with INIC2, implying that INIC2 can promote the
15
conversion of PbI2 to the perovskite phase. The similar polar intensity profiles along the ring of
16
0.98-1.02 Å-1 indicate that the orientation of perovskite is barely changed (Figure S3d).
17
Figure S4a exhibits the UV-vis absorption spectra of perovskite films without and with INIC2.
18
Clearly, compared with the pristine perovskite films, the absorption intensity of INIC2-perovskite hybrid
19
films is enhanced due to the larger grain size and higher crystallinity of perovskite.57 The transmission
20
and reflection spectra of the perovskite films without and with INIC2 (Figures S4b and c) indicate that 6 ACS Paragon Plus Environment
Page 7 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
the perovskite films with INIC2 exhibit slightly weaker transmittance and reflectance, further proving its
2
stronger absorption. However, the absorption edge is unchanged, indicating the bandgap of the
3
INIC2-perovskite hybrid films is same as that of the pristine perovskite film. We also measured the
4
absorption spectra of PbI2 solution without and with INIC2 (Figure S4d); new peaks at 430-500 and
5
570-740 nm were observed for PbI2 solution with INIC2 from the inset, indicating existence of
6
interaction between PbI2 and INIC2.46 Ultraviolet photoelectron spectroscopy (UPS) was conducted to
7
measure the energy levels of perovskite films without and with INIC2 (Figure S5a), and there is no
8
obvious change induced by INIC2, perhaps due to the trace amount of INIC2. The energy level diagram
9
of PSCs is shown in Figure S5b.
10
In order to further investigate the interaction between INIC2 and perovskite, X-ray photoelectron
11
spectroscopy (XPS) was used to measure the surface chemical states of Pb atoms in perovskite films.
12
Figure S6a shows the binding energies of valence electrons for two 4f orbitals of Pb (4f7/2 and 4f5/2).
13
Compared with the pristine perovskite film, the binding energies of C1s valence electrons show no shift
14
(Figure S6b), while the binding energies of Pb valence electrons in the INIC2-perovskite hybrid film
15
exhibits a slight shift toward lower values. Some atoms or atomic groups with lone pair electrons in
16
INIC2, such as S,46 C=O and C≡N,40 can form coordination bonding with under-coordinated Pb atoms.
17
The binding energy of Pb 4f orbitals decreases while acquiring electrons. The chemical interaction
18
between Pb atoms and INIC2 was investigated by fourier transform infrared (FTIR) spectroscopy
19
(Figure S6c). The stretching vibration of carbonyl (C=O) in INIC2 shifts to a lower wavenumber,
20
indicating existence of interaction between PbI2 and INIC2.58 Meanwhile, the trap density of states 7 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 8 of 27
1
(tDOS) of the entire devices was measured by thermal admittance spectroscopy (TAS) method (Figure
2
S6d). The tDOS with an energy depth of 0.50-0.60 eV is decreased from 1.7 × 1018 to 1.1 × 1018 cm-3
3
eV-1 after incorporating with INIC2, indicating that INIC2 plays an important role in defect passivation.
4
Photo and Device Physics. To investigate the charge extraction, the steady-state photoluminescence
5
(PL) and time-resolved PL (TRPL) spectra of glass/SnO2/perovskite and glass/SnO2/perovskite:INIC2
6
were measured. The PL intensity of the perovskite film incorporated with INIC2 becomes weaker than
7
that of the pristine perovskite film on glass/SnO2 substrate, indicating more efficient charge transfer at
8
the interface between perovskite and SnO2 (Figure 3a). The TRPL decay was measured with an
9
excitation at 470 nm, and fitted the data with a two-component exponential function (Figure 3b). The
10
fast (τ1), slow (τ2), and average lifetime (τave) are calculated and listed in Table S1. The τave of the
11
perovskite:INIC2 film is shorter than that of the pristine perovskite film on glass/SnO2 substrate,
12
suggesting a faster electron extraction from the INIC2-perovskite hybrid film to SnO2. We also
13
measured the PL and TRPL spectra of glass/perovskite (without and with INIC2) and glass/perovskite
14
(without and with INIC2)/HTL, where hole-transporting layer (HTL) is Spiro-OMeTAD. For
15
glass/perovskite (without and with INIC2), the PL intensity of the perovskite film with INIC2 becomes
16
weaker (Figure S7a); and its TRPL decay becomes faster (Figure S7c) relative to that without INIC2,
17
due to electron-transport property of n-type organic semiconductor INIC2. For glass/perovskite (without
18
and with INIC2)/HTL, the PL intensity of the perovskite with INIC2 becomes weaker (Figure S7b) and
19
its TRPL decay becomes faster (Figure S7d) relative to that without INIC2, suggesting that the hole
8 ACS Paragon Plus Environment
Page 9 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
extraction properties also get improved. Since the electrons are extracted by INIC2, the recombination of
2
electrons and holes decreases, facilitating hole extraction.
3
Transient absorption (TA) spectroscopy was performed to investigate ultrafast carrier dynamics in
4
perovskite and perovskite:INIC2 films. The samples were excited at 400 nm and probed by broadband
5
supercontinuum, and the experimental details are in Supporting Information. Since the majority
6
photoexcitation species are free carriers in perovskites, we used the bleach peak at ~750 nm as the
7
signature of carrier population dynamics.59-60 Figure 4a shows the evolution of TA probed at ~750 nm
8
of perovskite and perovskite:INIC2 on glass substrate. The similarity of TA kinetics in both samples
9
suggests that INIC2 molecules don’t form recombination centres in perovskite, consistent with the high
10
device performance. In Figure 4b, we also investigated the samples of perovskite and perovskite:INIC2
11
with SnO2 electron extraction layer. Comparing Figure 4b with Figure 4a, it clearly shows the shorter
12
carrier lifetime due to the carrier recombination at the SnO2/perovskite interface; similar dynamic
13
behaviour has been reported in perovskite on electron extraction layer.61-62 By analyzing
14
sub-nanosecond TA decays, we obtained effective lifetimes 439 ps and 335 ps of perovskite and
15
perovskite:INIC2 on SnO2, respectively. The slightly faster decay is ascribed to the more efficient
16
carrier transport in the perovskite:INIC2 samples with larger crystal domain size and less defects, in
17
agreement with the TRPL experiment.
18
To further explore the charge transfer and recombination dynamics in devices, transient photovoltage
19
(TPV) and photocurrent (TPC) measurements were carried out. The TPV and TPC measurements were
20
performed under dark condition, excited by a 532 nm pulse laser with certain intensity, and the data are 9 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 10 of 27
1
fitted by bi-exponential decay function. As shown in Figure S8a, the devices with INIC2 exhibit a
2
photovoltage decay time of 0.44 ms, which is longer than that of the control devices without INIC2
3
(0.39 ms). The prolonged lifetime suggests that less carrier recombination takes place in the devices
4
with INIC2. From the TPC measurement (Figure S8b), the devices with INIC2 yield a larger
5
photocurrent with a shorter charge transfer time (1.68 μs) compared with the control devices (2.58 μs),
6
indicating improved electron transport and charge collection.
7
Photovoltaics. The photovoltaic parameters of the PSCs with INIC2 in different concentrations are
8
summarized in Table S2. The optimal concentration of INIC2 is 0.3 mg mL-1. The optimized devices
9
with INIC2 exhibit a peak PCE of 21.7% with a short circuit current density (JSC) of 23.8 mA cm-2, an
10
open circuit voltage (VOC) of 1.13 V, and a fill factor (FF) of 80.3%, which is higher than the control
11
devices without INIC2: a maximum PCE of 19.6%, JSC of 23.6 mA cm-2, VOC of 1.08 V and FF of 77.2%
12
(Figure 5a, Table 1). The increase in VOC and FF for PSCs with INIC2 benefits from more effective
13
charge transport and less carrier recombination. The hysteresis is similar in devices without and with
14
INIC2 (Figure S9). The external quantum efficiency (EQE) of the devices with INIC2 is higher than
15
that of the control devices without INIC2 (Figure 5b), and the calculated JSC from integration of EQE
16
spectra of PSCs with INIC2 is 23.3 mA cm-2, which is higher than that of the control devices (22.5 mA
17
cm-2). The device with INIC2 exhibits a stabilized efficiency of 20.5% over 60 s (Figure 5c), whereas
18
the control device presents a stabilized PCE of 18.3%. The performance of PSCs with INIC2 exhibits
19
good reproducibility (Figure S9c).
20
We also studied the stability of the unencapsulated PSCs without and with INIC2 under ambient 10 ACS Paragon Plus Environment
Page 11 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
conditions (humidity about 30% and temperature about 25 °C) in the dark (Figure 5d). The PCE of the
2
control device without INIC2 retained 20% of its initial value over 60 days, while the optimized device
3
with INIC2 retained about 60% of its initial value. Apparently, PSCs with INIC2 exhibited significantly
4
improved stability due to the higher quality perovskite film with larger grain sizes and better
5
crystallinity to resist the moisture penetration.63
6
Conclusion
7
In summary, we incorporated a fused ring electron acceptor (INIC2) into the PbI2 solution to prepare
8
FREA-perovskite hybrid films. The SEM, XRD and GIWAXS measurements indicate the perovskite
9
films with INIC2 exhibit larger grain sizes and stronger crystallinity relative to the pristine perovskite
10
films. FTIR, XPS spectra and tDOS measurements suggest that the electron-rich atoms in INIC2 can
11
form coordination bonding with under-coordinated Pb atoms and passivate the trap states in the
12
perovskite films. Steady-state and time-resolved PL spectra as well as TA measurements reveal that
13
INIC2 is beneficial to efficient electron extraction and collection. TPC measurement demonstrates the
14
faster charge transfer in devices with INIC2, while TPV measurement demonstrates that carrier
15
recombination is reduced due to the defects passivation by INIC2. As a result, the PSCs with INIC2
16
exhibit PCEs up to 21.7%, higher than that of the control devices without INIC2 (19.6%). Moreover, the
17
devices based on INIC2-perovskite hybrid films exhibit better stability. This work demonstrates that
18
FREA-perovskite hybrid is a promising platform to fabricate organic-inorganic hybrid solar cells with
19
simple preparation, high efficiency and good stability.
20 11 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 12 of 27
1
Supporting Information
2
The Supporting Information is available free of charge on the ACS Publications website.
3
Experimental details including materials, device fabrication and measurements, the details of tDOS and
4
TA, device data and additional characterization data, such as EDX, SEM, XRD, UV-vis, transmission,
5
reflection, UPS, XPS, FTIR, tDOS, PL, TRPL, TPV and TPC.
6 7
Corresponding Author
8
*
[email protected] (X.Z.),
[email protected] (H.Z.)
9
ORCID
10
Xiaowei Zhan: 0000-0002-1006-3342, Huanping Zhou: 0000-0003-4882-5354
11
Notes
12
The authors declare no competing financial interest.
13 14
Acknowledgements
15
X.Z. acknowledges the funding support from the National Natural Science Foundation of China (NSFC,
16
No. 21673011). H.Z. thanks the funding support from the NSFC (Nos. 51722201, 51672008, 91733301),
17
National Key Research and Development Program of China (No. 2017YFA0206701), and Beijing
18
Natural Science Foundation (No. 4182026).
19 20
References 12 ACS Paragon Plus Environment
Page 13 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
(1) Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T., Organometal Halide Perovskites as Visible-Light
2
Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131, 6050.
3
(2) Im, J.-H.; Lee, C.-R.; Lee, J.-W.; Park, S.-W.; Park, N.-G., 6.5% Efficient Perovskite
4
Quantum-Dot-Sensitized Solar Cell. Nanoscale 2011, 3, 4088.
5
(3) Kim, H.-S.; Lee, C.-R.; Im, J.-H.; Lee, K.-B.; Moehl, T.; Marchioro, A.; Moon, S.-J.;
6
Humphry-Baker, R.; Yum, J.-H.; Moser, J. E.; Graetzel, M.; Park, N.-G., Lead Iodide Perovskite
7
Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%.
8
Sci. Rep. 2012, 2, 591.
9
(4) Burschka, J.; Pellet, N.; Moon, S.-J.; Humphry-Baker, R.; Gao, P.; Nazeeruddin, M. K.; Graetzel, M.,
10
Sequential Deposition as a Route to High-Performance Perovskite-Sensitized Solar Cells. Nature 2013,
11
499, 316.
12
(5) Zhou, H.; Chen, Q.; Li, G.; Luo, S.; Song, T.-b.; Duan, H.-S.; Hong, Z.; You, J.; Liu, Y.; Yang, Y.,
13
Interface Engineering of Highly Efficient Perovskite Solar Cells. Science 2014, 345, 542.
14
(6) Green, M. A.; Bein, T., Photovoltaics Perovskite Cells Charge Forward. Nat. Mater. 2015, 14, 559.
15
(7) Yang, W. S.; Park, B.-W.; Jung, E. H.; Jeon, N. J.; Kim, Y. C.; Lee, D. U.; Shin, S. S.; Seo, J.; Kim,
16
E. K.; Noh, J. H.; Seok, S. I., Iodide Management in Formamidinium-Lead-Halide-Based Perovskite
17
Layers for Efficient Solar Cells. Science 2017, 356, 1376.
18
(8) Eperon, G. E.; Burlakov, V. M.; Docampo, P.; Goriely, A.; Snaith, H. J., Morphological Control for
19
High Performance, Solution-Processed Planar Heterojunction Perovskite Solar Cells. Adv. Funct. Mater.
20
2014, 24, 151. 13 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 14 of 27
1
(9) Wu, X.; Trinh, M. T.; Niesner, D.; Zhu, H.; Norman, Z.; Owen, J. S.; Yaffe, O.; Kudisch, B. J.; Zhu,
2
X. Y., Trap States in Lead Iodide Perovskites. J. Am. Chem. Soc. 2015, 137, 2089.
3
(10) Bi, D.; Yi, C.; Luo, J.; Decoppet, J.-D.; Zhang, F.; Zakeeruddin, S. M.; Li, X.; Hagfeldt, A.; Gratzel,
4
M., Polymer-Templated Nucleation and Crystal Growth of Perovskite Films for Solar Cells with
5
Efficiency Greater Than 21%. Nat. Energy 2016, 1, 16142.
6
(11) Zhang, F.; Shi, W.; Luo, J.; Pellet, N.; Yi, C.; Li, X.; Zhao, X.; Dennis, T. J. S.; Li, X.; Wang, S.;
7
Xiao, Y.; Zakeeruddin, S. M.; Bi, D.; Graetzel, M., Isomer-Pure Bis-Pcbm-Assisted Crystal Engineering
8
of Perovskite Solar Cells Showing Excellent Efficiency and Stability. Adv. Mater. 2017, 29, 1606806.
9
(12) Shao, Y.; Xiao, Z.; Bi, C.; Yuan, Y.; Huang, J., Origin and Elimination of Photocurrent Hysteresis
10
by Fullerene Passivation in CH3NH3PbI3 Planar Heterojunction Solar Cells. Nat. Commun. 2014, 5,
11
5784.
12
(13) Chen, Q.; Zhou, H.; Song, T.-B.; Luo, S.; Hong, Z.; Duan, H.-S.; Dou, L.; Liu, Y.; Yang, Y.,
13
Controllable Self-Induced Passivation of Hybrid Lead Iodide Perovskites toward High Performance
14
Solar Cells. Nano Lett. 2014, 14, 4158.
15
(14) Nie, W.; Tsai, H.; Asadpour, R.; Blancon, J.-C.; Neukirch, A. J.; Gupta, G.; Crochet, J. J.;
16
Chhowalla, M.; Tretiak, S.; Alam, M. A.; Wang, H.-L.; Mohite, A. D., High-Efficiency
17
Solution-Processed Perovskite Solar Cells with Millimeter-Scale Grains. Science 2015, 347, 522.
18
(15) Kim, H.-B.; Choi, H.; Jeong, J.; Kim, S.; Walker, B.; Song, S.; Kim, J. Y., Mixed Solvents for the
19
Optimization of Morphology in Solution-Processed, Inverted-Type Perovskite/Fullerene Hybrid Solar
20
Cells. Nanoscale 2014, 6, 6679. 14 ACS Paragon Plus Environment
Page 15 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
(16) Dualeh, A.; Gao, P.; Seok, S. I.; Nazeeruddin, M. K.; Graetzel, M., Thermal Behavior of
2
Methylammonium Lead-Trihalide Perovskite Photovoltaic Light Harvesters. Chem. Mater. 2014, 26,
3
6160.
4
(17) Xiao, Z.; Dong, Q.; Bi, C.; Shao, Y.; Yuan, Y.; Huang, J., Solvent Annealing of Perovskite-Induced
5
Crystal Growth for Photovoltaic-Device Efficiency Enhancement. Adv. Mater. 2014, 26, 6503.
6
(18) Lee, J.-W.; Kim, H.-S.; Park, N.-G., Lewis Acid-Base Adduct Approach for High Efficiency
7
Perovskite Solar Cells. Acc. Chem. Res. 2016, 49, 311.
8
(19) Jeon, N. J.; Noh, J. H.; Kim, Y. C.; Yang, W. S.; Ryu, S.; Seok, S. I., Solvent Engineering for
9
High-Performance Inorganic-Organic Hybrid Perovskite Solar Cells. Nat. Mater. 2014, 13, 897.
10
(20) Li, T.; Pan, Y.; Wang, Z.; Xia, Y.; Chen, Y.; Huang, W., Additive Engineering for Highly Efficient
11
Organic-Inorganic Halide Perovskite Solar Cells: Recent Advances and Perspectives. J. Mater. Chem. A
12
2017, 5, 12602.
13
(21) Heo, J. H.; Song, D. H.; Han, H. J.; Kim, S. Y.; Kim, J. H.; Kim, D.; Shin, H. W.; Ahn, T. K.; Wolf,
14
C.; Lee, T.-W.; Im, S. H., Planar CH3NH3PbI3 Perovskite Solar Cells with Constant 17.2% Average
15
Power Conversion Efficiency Irrespective of the Scan Rate. Adv. Mater. 2015, 27, 3424.
16
(22) McMeekin, D. P.; Wang, Z.; Rehman, W.; Pulvirenti, F.; Patel, J. B.; Noel, N. K.; Johnston, M. B.;
17
Marder, S. R.; Herz, L. M.; Snaith, H. J., Crystallization Kinetics and Morphology Control of
18
Formamidinium-Cesium Mixed-Cation Lead Mixed-Halide Perovskite Via Tunability of the Colloidal
19
Precursor Solution. Adv. Mater. 2017, 29, 1607039.
15 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 16 of 27
1
(23) Seo, J.-Y.; Matsui, T.; Luo, J.; Correa-Baena, J.-P.; Giordano, F.; Saliba, M.; Schenk, K.;
2
Ummadisingu, A.; Domanski, K.; Hadadian, M.; Hagfeldt, A.; Zakeeruddin, S. M.; Steiner, U.; Graetzel,
3
M.; Abate, A., Ionic Liquid Control Crystal Growth to Enhance Planar Perovskite Solar Cells Efficiency.
4
Adv. Energy Mater. 2016, 6, 1600767.
5
(24) Zhang, Y.; Gao, P.; Oveisi, E.; Lee, Y.; Jeangros, Q.; Grancini, G.; Paek, S.; Feng, Y.; Nazeeruddin,
6
M. K., PbI2-HMPA Complex Pretreatment for Highly Reproducible and Efficient CH3NH3PbI3
7
Perovskite Solar Cells. J. Am. Chem. Soc. 2016, 138, 14380.
8
(25) Guo, Y.; Sato, W.; Shoyama, K.; Nakamura, E., Sulfamic Acid-Catalyzed Lead Perovskite
9
Formation for Solar Cell Fabrication on Glass or Plastic Substrates. J. Am. Chem. Soc. 2016, 138, 5410.
10
(26) Zhao, W.; Yang, D.; Liu, S. F., Organic-Inorganic Hybrid Perovskite with Controlled Dopant
11
Modification and Application in Photovoltaic Device. Small 2017, 13, 1604153.
12
(27) Wang, J. T.-W.; Wang, Z.; Pathak, S.; Zhang, W.; deQuilettes, D. W.; Wisnivesky-Rocca-Rivarola,
13
F.; Huang, J.; Nayak, P. K.; Patel, J. B.; Yusof, H. A. M.; Vaynzof, Y.; Zhu, R.; Ramirez, I.; Zhang, J.;
14
Ducati, C.; Grovenor, C.; Johnston, M. B.; Ginger, D. S.; Nicholas, R. J.; Snaith, H. J., Efficient
15
Perovskite Solar Cells by Metal Ion Doping. Energy Environ. Sci. 2016, 9, 2892.
16
(28) Zhao, W.; Yao, Z.; Yu, F.; Yang, D.; Liu, S., Alkali Metal Doping for Improved CH3NH3PbI3
17
Perovskite Solar Cells. Adv. Sci. 2018, 5, 1700131.
18
(29) Masi, S.; Rizzo, A.; Munir, R.; Listorti, A.; Giuri, A.; Corcione, C. E.; Treat, N. D.; Gigli, G.;
19
Amassian, A.; Stingelin, N.; Colella, S., Organic Gelators as Growth Control Agents for Stable and
20
Reproducible Hybrid Perovskite-Based Solar Cells. Adv. Energy Mater. 2017, 7, 1602600. 16 ACS Paragon Plus Environment
Page 17 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
(30) Zhang, C.-C.; Li, M.; Wang, Z.-K.; Jiang, Y.-R.; Liu, H.-R.; Yang, Y.-G.; Gao, X.-Y.; Ma, H.,
2
Passivated Perovskite Crystallization and Stability in Organic-Inorganic Halide Solar Cells by Doping a
3
Donor Polymer. J. Mater. Chem. A 2017, 5, 2572.
4
(31) Wei, J.; Li, H.; Zhao, Y.; Zhou, W.; Fu, R.; Leprince-Wang, Y.; Yu, D.; Zhao, Q., Suppressed
5
Hysteresis and Improved Stability in Perovskite Solar Cells with Conductive Organic Network. Nano
6
Energy 2016, 26, 139.
7
(32) Jiang, J.; Wang, Q.; Jin, Z.; Zhang, X.; Lei, J.; Bin, H.; Zhang, Z.-G.; Li, Y.; Liu, S., Polymer
8
Doping for High-Efficiency Perovskite Solar Cells with Improved Moisture Stability. Adv. Energy
9
Mater. 2018, 8, 1701757.
10
(33) Zhang, Y.; Zhuang, X.; Zhou, K.; Cai, C.; Hu, Z.; Zhang, J.; Zhu, Y., Amorphous Polymer with
11
C=O to Improve the Performance of Perovskite Solar Cells. J. Mater. Chem. C 2017, 5, 9037.
12
(34) Li, F.; Yuan, J.; Ling, X.; Zhang, Y.; Yang, Y.; Cheung, S. H.; Ho, C. H. Y.; Gao, X.; Ma, W., A
13
Universal Strategy to Utilize Polymeric Semiconductors for Perovskite Solar Cells with Enhanced
14
Efficiency and Longevity. Adv. Funct. Mater. 2018, 28, 1706377.
15
(35) Zuo, L.; Guo, H.; deQuilettes, D. W.; Jariwala, S.; De Marco, N.; Dong, S.; DeBlock, R.; Ginger, D.
16
S.; Dunn, B.; Wang, M.; Yang, Y., Polymer-Modified Halide Perovskite Films for Efficient and Stable
17
Planar Heterojunction Solar Cells. Sci. Adv. 2017, 3, 1700106.
18
(36) Qin, L.; Wu, L.; Kattel, B.; Li, C.; Zhang, Y.; Hou, Y.; Wu, J.; Chan, W.-L., Using Bulk
19
Heterojunctions and Selective Electron Trapping to Enhance the Responsivity of Perovskite-Graphene
20
Photodetectors. Adv. Funct. Mater. 2017, 27, 1704173. 17 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 18 of 27
1
(37) Xu, J.; Buin, A.; Ip, A. H.; Li, W.; Voznyy, O.; Comin, R.; Yuan, M.; Jeon, S.; Ning, Z.; McDowell,
2
J. J.; Kanjanaboos, P.; Sun, J.-P.; Lan, X.; Quan, L. N.; Kim, D. H.; Hill, I. G.; Maksymovych, P.;
3
Sargent, E. H., Perovskite-Fullerene Hybrid Materials Suppress Hysteresis in Planar Diodese. Nat.
4
Commun. 2015, 6, 7081.
5
(38) Chiang, C.-H.; Wu, C.-G., Bulk Heterojunction Perovskite-PCBM Solar Cells with High Fill Factor.
6
Nat. Photon. 2016, 10, 196.
7
(39) Fang, Y.; Bi, C.; Wang, D.; Huang, J., The Functions of Fullerenes in Hybrid Perovskite Solar Cells.
8
ACS Energy Lett. 2017, 2, 782.
9
(40) Lin, Y.; Shen, L.; Dai, J.; Deng, Y.; Wu, Y.; Bai, Y.; Zheng, X.; Wang, J.; Fang, Y.; Wei, H.; Ma,
10
W.; Zeng, X. C.; Zhan, X.; Huang, J., Pi-Conjugated Lewis Base: Efficient Trap-Passivation and
11
Charge-Extraction for Hybrid Perovskite Solar Cells. Adv. Mater. 2017, 29, 1604545.
12
(41) Meng, F.; Liu, K.; Dai, S.; Shi, J.; Zhang, H.; Xu, X.; Li, D.; Zhan, X., A Perylene Diimide Based
13
Polymer: A Dual Function Interfacial Material for Efficient Perovskite Solar Cells. Mater. Chem. Front.
14
2017, 1, 1079.
15
(42) Zhang, M.; Zhu, J.; Liu, K.; Zheng, G.; Zhao, G.; Li, L.; Meng, Y.; Guo, T.; Zhou, H.; Zhan, X., A
16
Low Temperature Processed Fused-Ring Electron Transport Material for Efficient Planar Perovskite
17
Solar Cells. J. Mater. Chem. A 2017, 5, 24820.
18
(43) Liu, K.; Dai, S.; Meng, F.; Shi, J.; Li, Y.; Wu, J.; Meng, Q.; Zhan, X., Fluorinated Fused
19
Nonacyclic Interfacial Materials for Efficient and Stable Perovskite Solar Cells. J. Mater. Chem. A 2017,
20
5, 21414. 18 ACS Paragon Plus Environment
Page 19 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
(44) Lian, J.; Lu, B.; Niu, F.; Zeng, P.; Zhan, X., Electron-Transport Materials in Perovskite Solar Cells.
2
Small Methods 2018, DOI: 10.1002/smtd.201800082.
3
(45) Niu, T.; Lu, J.; Munir, R.; Li, J.; Barrit, D.; Zhang, X.; Hu, H.; Yang, Z.; Amassian, A.; Zhao, K.;
4
Liu, S., Stable High-Performance Perovskite Solar Cells Via Grain Boundary Passivation. Adv. Mater.
5
2018, 30, 1706576.
6
(46) Qin, M.; Cao, J.; Zhang, T.; Mai, J.; Lau, T. K.; Zhou, S.; Zhou, Y.; Wang, J.; Hsu, Y. J.; Zhao, N.;
7
Xu, J.; Zhan, X.; Lu, X., Fused-Ring Electron Acceptor ITIC-Th: A Novel Stabilizer for Halide
8
Perovskite Precursor Solution. Adv. Energy Mater. 2018, 8, 1703399.
9
(47) Lin, Y.; Wang, J.; Zhang, Z. G.; Bai, H.; Li, Y.; Zhu, D.; Zhan, X., An Electron Acceptor
10
Challenging Fullerenes for Efficient Polymer Solar Cells. Adv. Mater. 2015, 27, 1170.
11
(48) Lin, Y.; He, Q.; Zhao, F.; Huo, L.; Mai, J.; Lu, X.; Su, C.-J.; Li, T.; Wang, J.; Zhu, J.; Sun, Y.;
12
Wang, C.; Zhan, X., A Facile Planar Fused-Ring Electron Acceptor for as-Cast Polymer Solar Cells with
13
8.71% Efficiency. J. Am. Chem. Soc. 2016, 138, 2973.
14
(49) Lin, Y.; Zhao, F.; He, Q.; Huo, L.; Wu, Y.; Parker, T. C.; Ma, W.; Sun, Y.; Wang, C.; Zhu, D.;
15
Heeger, A. J.; Marder, S. R.; Zhan, X., High-Performance Electron Acceptor with Thienyl Side Chains
16
for Organic Photovoltaics. J. Am. Chem. Soc. 2016, 138, 4955.
17
(50) Dai, S.; Zhao, F.; Zhang, Q.; Lau, T.-K.; Li, T.; Liu, K.; Ling, Q.; Wang, C.; Lu, X.; You, W.; Zhan,
18
X., Fused Nonacyclic Electron Acceptors for Efficient Polymer Solar Cells. J. Am. Chem. Soc. 2017,
19
139, 1336.
19 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 20 of 27
1
(51) Wang, J.; Zhang, J.; Xiao, Y.; Xiao, T.; Zhu, R.; Yan, C.; Fu, Y.; Lu, G.; Lu, X.; Marder, S. R.;
2
Zhan, X., Effect of Isomerization on High-Performance Nonfullerene Electron Acceptors. J. Am. Chem.
3
Soc. 2018, 140, 9140.
4
(52) Yan, C.; Barlow, S.; Wang, Z.; Yan, H.; Jen, A. K. Y.; Marder, S. R.; Zhan, X., Non-Fullerene
5
Acceptors for Organic Solar Cells. Nat. Rev. Mater. 2018, 3, 18003.
6
(53) Auer, S.; Frenkel, D., Suppression of Crystal Nucleation in Polydisperse Colloids Due to Increase
7
of the Surface Free Energy. Nature 2001, 413, 711.
8
(54) Cacciuto, A.; Auer, S.; Frenkel, D., Onset of Heterogeneous Crystal Nucleation in Colloidal
9
Suspensions. Nature 2004, 428, 404.
10
(55) Pang, S.; Zhou, Y.; Wang, Z.; Yang, M.; Krause, A. R.; Zhou, Z.; Zhu, K.; Padture, N. P.; Cui, G.,
11
Transformative
12
Room-Temperature Solid-Gas Interaction between HPbI3-CH3NH2 Precursor Pair. J. Am. Chem. Soc.
13
2016, 138, 750.
14
(56) Yin, J.; Qu, H.; Cao, J.; Tai, H.; Li, J.; Zheng, N., Vapor-Assisted Crystallization Control toward
15
High Performance Perovskite Photovoltaics with over 18% Efficiency in the Ambient Atmosphere. J.
16
Mater. Chem. A 2016, 4, 13203.
17
(57) Im, J.-H.; Jang, I.-H.; Pellet, N.; Grätzel, M.; Park, N.-G., Growth of CH3NH3PbI3 Cuboids with
18
Controlled Size for High-Efficiency Perovskite Solar Cells. Nat. Nanotech. 2014, 9, 927.
Evolution
of
Organolead
Triiodide
Perovskite
20 ACS Paragon Plus Environment
Thin
Films
from
Strong
Page 21 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
1
(58) Li, X.; Chen, C. C.; Cai, M.; Hua, X.; Xie, F.; Liu, X.; Hua, J.; Long, Y. T.; Tian, H.; Han, L.,
2
Efficient Passivation of Hybrid Perovskite Solar Cells Using Organic Dyes with -COOH Functional
3
Group. Adv. Energy Mater. 2018, 8, 1800715.
4
(59) Xing, G.; Mathews, N.; Sun, S.; Lim, S. S.; Lam, Y. M.; Grätzel, M.; Mhaisalkar, S.; Sum, T. C.,
5
Long-Range Balanced Electron- and Hole-Transport Lengths in Organic-Inorganic CH3NH3PbI3.
6
Science 2013, 342, 344.
7
(60) Chen, K.; Barker, A. J.; Morgan, F. L. C.; Halpert, J. E.; Hodgkiss, J. M., Effect of Carrier
8
Thermalization Dynamics on Light Emission and Amplification in Organometal Halide Perovskites. J.
9
Phys. Chem. Lett. 2015, 6, 153.
10
(61) Zhu, Z.; Ma, J.; Wang, Z.; Cheng, M.; Fan, Z.; Du, L.; Yang, B.; Fan, L.; He, Y.; Phillips, D. L.;
11
Yang, S., Efficiency Enhancement of Perovskite Solar Cells through Fast Electron Extraction: The Role
12
of Graphene Quantum Dots. J. Am. Chem. Soc. 2014, 136, 3760.
13
(62) Baena, J. P. C.; Steier, L.; Tress, W.; Saliba, M.; Neutzner, S.; Matsui, T.; Giordano, F.; Jacobsson,
14
J.; Kandada, A. R. S.; Zakeeruddin, S. M.; Petrozza, A.; Abate A.; Nazeeruddin, M. K.; Grätzel, M.;
15
Hagfeldt, A., Highly Efficient Planar Perovskite Solar Cells through Band Alignment Engineering.
16
Energy Environ. Sci. 2015, 8, 2928.
17
(63) Xue, J.; Lee, J.-W.; Dai, Z.; Wang, R.; Nuryyeva, S.; Liao, M. E.; Chang, S.-Y.; Meng, L.; Meng,
18
D.; Sun, P.; Lin, O.; Goorsky, M. S.; Yang, Y., Surface Ligand Management for Stable FAPbI3
19
Perovskite Quantum Dot Solar Cells. Joule 2018, 2, 1866.
21 ACS Paragon Plus Environment
Journal of the American Chemical Society
1 2
Figure 1. Device structure of PSCs and chemical structure of INIC2.
3
(a)
(b)
PbI2 PbI2 (INIC2)
Intensity (a.u.) 10
4
perovskite perovskite (INIC2)
Intensity (a.u.)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 22 of 27
20
30
40
50
10
60
20
30
40
2 Theta (degree)
2 Theta (degree)
5
22 ACS Paragon Plus Environment
50
60
Page 23 of 27
1
Figure 2. (a) XRD patterns of PbI2 films without and with INIC2 (0.3 mg mL-1); (b) XRD patterns of
2
perovskite films without and with INIC2 (0.3 mg mL-1); GIWAXS patterns of perovskite films without
3
INIC2 (c) and with INIC2 (0.3 mg mL-1) (d).
3
8.0x10
(b)
w/o INIC2 w/ INIC2
PL intensity (a.u.)
(a)
PL intensity (a.u.)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
3
6.0x10
3
4.0x10
3
2.0x10
0.0 700
750
800
850
1
0.1
0.01
w/o INIC2 w/ INIC2 fitting curves
0
4
50
100
150
200
Time (ns)
Wavelength (nm)
5
Figure 3. (a) Steady-state PL and (b) TRPL spectra of perovskite without and with INIC2 (0.3 mg mL-1)
6
on glass/SnO2 substrate.
23 ACS Paragon Plus Environment
Journal of the American Chemical Society
1 2
Figure 4. Transient absorption kinetic traces of (a) perovskite (PVSK) and PVSK:INIC2 on glass
3
substrates probed at 750 nm after the laser excitation at 400 nm at a pump fluence of 1.8 µJ cm-2 with the
4
corresponding spectra at 10 ps in the inset; (b) SnO2/PVSK and SnO2/PVSK:INIC2 on glass substrates
5
probed at 750 nm after the laser excitation at 400 nm at a pump fluence of 0.9 µJ cm-2 which are fitted to
6
double exponential function (blue dashes). The extracted effective lifetimes are given in the brackets.
20
80
15 10 PSCs w/o INIC2 PSCs w/ INIC2
5
7
20 16
60
12 40
8
20
0 -5 -0.2
24
0.0
0.2
0.4
0.6
0.8
1.0
0 300
1.2
PSCs w/o INIC2 PSCs w/ INIC2
400
500
600
700
Wavelength (nm)
Voltage (V)
24 ACS Paragon Plus Environment
4 800
0
J (mA cm -2)
(b) 100
EQE (%)
(a) 25
J (mA cm -2)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 24 of 27
Page 25 of 27
(c) 25
(d) 100
10
10 PSCs w/o INIC2 @ 0.88 V
0
1
5
PSCs w/ INIC2 @ 0.98 V
5
0
10
20
30
40
50
0 60
Normalized PCE (%)
15
15
J (mA cm -2)
20
20
J (mA cm -2)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Journal of the American Chemical Society
80 60 40 20 0
PSCs w/o INIC2 PSCs w/ INIC2
0
10
Time (s)
20
30
40
50
60
Time (day)
2
Figure 5. (a) J-V curves and (b) EQE spectra of PSCs without and with INIC2 (0.3 mg mL-1); (c)
3
steady-state measurement of current for PSCs without and with INIC2 (0.3 mg mL-1); (d) stability tests
4
of the PSCs without and with INIC2 (0.3 mg mL-1) under ambient conditions.
25 ACS Paragon Plus Environment
Journal of the American Chemical Society 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 26 of 27
1 2
Table 1. Photovoltaic parameters of the optimized PSCs under different scanning direction.
w/o INIC2
w/ INIC2
3
a
scanning
JSC
calculated JSCa
direction
(mA cm-2)
(mA cm-2)
reverse
23.6
forward
PCE (%)
VOC
FF
(V)
(%)
best
average
22.5
1.08
77.2
19.6
17.9
22.9
-
1.06
74.9
18.1
-
reverse
23.8
23.3
1.13
80.3
21.7
19.8
forward
23.7
-
1.11
75.4
19.9
-
Calculated by integration of EQE spectra.
26 ACS Paragon Plus Environment
Page 27 of 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
1
Journal of the American Chemical Society
TOC image
2
27 ACS Paragon Plus Environment