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Low-Cost and Highly Efficient Carbon-Based Perovskite
Solar Cells Exhibiting Excellent Long-Term Operational
and UV Stability
Neha Arora, M. Ibrahim Dar,* Seckin Akin, Ryusuke Uchida, Thomas Baumeler,
Yuhang Liu, Shaik Mohammed Zakeeruddin, and Michael Grätzel*
light absorbers highly promising for
harnessing solar photons.[5–9] However,
PSCs displaying record power-conversion efficiencies (PCEs) employ in general noble metals as back contacts and
highly expensive organic hole conductors, rendering their cost prohibitive and
impairing their long-term operational stability.[1,10,11] These challenges need to be
addressed by identifying combinations
of hole conducting materials with back
contacts that are appropriate for largescale deployment of PSCs.[12,13] Previously, we have reported Au-based PSCs
containing CuSCN, as extremely cheap
and stable hole conductor.[14] However,
further critical advances in device engineering are warranted to replace the Ag
and Au back contacts with a low-cost
material without compromising the PSC
performance. Of the various candidates,
carbon, which is cheap and conductive, has been considered
as a promising hole collecting material.[15] Despite its enticing
benefits, the true design of a robust and highly efficient architecture is still missing. Moreover, recent efforts to lower the
device costs of the PSCs using carbon-based back contacts
have compromised on affordability, stability, or the PCE.[16–21]
The main challenges that remain to be addressed to exploit the
full potential of PSCs are; 1) reaching high efficiencies without
using prohibitively expensive components, like spiro-MeOTAD,
poly(triaryl amine) (PTAA), C60 and its derivatives as well as Au
or Ag contacts, 2) ascertaining long-term operational stability,
and 3) attaining long-term ultraviolet (UV)-stability. Thus far a
comprehensive study tackling all these issues is lacking from
the vast PSC-based research.
To address the above-mentioned issues, we designed a noble
metal-free PSC configuration using carbon as a back contact
and CuSCN as hole conductor both being deposited at room
temperature. Apart from reaching a PCE exceeding 18%, a
record for carbon-based architecture involving inorganic hole
conductor,[22,23] these PSCs demonstrate extraordinary stability
by retaining ≈95% of their initial PCEs after 2000 h under continuous full-sun illumination at the maximum power point at
60 °C. Importantly, we observe that using this CuSCN/C configuration also assures remarkable stability under UV light in
contrast to the spiro-MeOTAD based devices.
Today’s perovskite solar cells (PSCs) mostly use components, such as organic
hole conductors or noble metal back contacts, that are very expensive or
cause degradation of their photovoltaic performance. For future large-scale
deployment of PSCs, these components need to be replaced with costeffective and robust ones that maintain high efficiency while ascertaining
long-term operational stability. Here, a simple and low-cost PSC architecture
employing dopant-free TiO2 and CuSCN as the electron and hole conductor,
respectively, is introduced while a graphitic carbon layer deposited at room
temperature serves as the back electrical contact. The resulting PSCs show
efficiencies exceeding 18% under standard AM 1.5 solar illumination and
retain ≈95% of their initial efficiencies for >2000 h at the maximum power
point under full-sun illumination at 60 °C. In addition, the CuSCN/carbon-based
PSCs exhibit remarkable stability under ultraviolet irradiance for >1000
h while under similar conditions, the standard spiro-MeOTAD/Au based
devices degrade severely.
The accelerated research on perovskite solar cells (PSCs)
can strongly promote the transition from fossil to alternative
renewable energy sources.[1–4] The remarkable optoelectronic
properties including high absorption coefficient, large diffusion lengths, and high carrier mobility render perovskite
Dr. N. Arora, Dr. M. I. Dar, Dr. S. Akin, R. Uchida, T. Baumeler, Dr. Y. Liu,
Dr. S. M. Zakeeruddin, Prof. M. Grätzel
Laboratory of Photonics and Interfaces
Department of Chemistry and Chemical Engineering
École Polytechnique Fédérale de Lausanne
Lausanne CH-1015, Switzerland
E-mail: ibrahim.dar@epfl.ch; michael.graetzel@epfl.ch
Dr. S. Akin
Department of Metallurgical and Materials Engineering
Karamanoglu Mehmetbey University
Karaman 70100, Turkey
R. Uchida
Institute for Energy and Material Food Resources
Technology Innovation Division
Panasonic Corporation
3-1-1 Yagumo-naka-machi
Moriguchi, Osaka 570-8501, Japan
The ORCID identification number(s) for the author(s) of this article
can be found under https://doi.org/10.1002/smll.201904746.
DOI: 10.1002/smll.201904746
Small 2019, 15, 1904746
1904746 (1 of 6)
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Communication
The deposition of perovskite light absorber and hole conductor was carried out in a dry air glove box under controlled
atmospheric conditions with humidity 80% of their photovoltaic
performance after exposing to the UV radiation for >200 h
(Figure 3B). The degradation observed in case of TiO2/perovskite/spiro-MeOTAD based devices has been attributed to the
well-known photocatalytic activity of TiO2 under ultraviolet illumination.[35,36] To mitigate this UV instability issue, we deposited a thin layer (85% of their initial performance after
exposing to the UV radiation for >1000 h, which allows us to
conclude that SnO2/TiO2 bilayer used with CuSCN/C based
devices benefits the UV stability. This clearly demonstrates that
both the spiro-MeOTAD and bare TiO2 components are more
susceptible to the UV light, providing a deeper insight into a
critical role that hole conductor plays in dictating the stability of
PSCs.[40–43] The promising UV-stability results further establish
that issues associated with TiO2 layer could be simply mitigated
by introducing a thin layer of amorphous SnO2 without compromising on the PCE of solar cells.
In summary, PSCs based on extremely expensive components including hole conductor and gold back contact is far
from commercialization. Therefore, these expensive and sensitive components need to be replaced with the cost-effective
ones from the perovskite solar cells architecture, while maintaining high efficiency and simultaneously improving the
long-term operational stability. To address all these issues, we
systematically engineered the architecture for low-cost perovskite solar cells employing CuSCN layer as the hole conductor
and highly graphitic carbon layer deposited at room temperature as the back contact. The remarkable light-harvesting efficiency was realized by meticulously tailoring the bandgap of
the absorber layer. The PSCs showing efficiencies greater than
18% under standard illumination, which retained ≈95% of their
initial efficiencies for >2000 h at the maximum power point
under full-sun illumination. In addition, the CuSCN/carbonbased PSCs exhibited highly promising stability under UV
irradiance for >1000 h. By contrast, under similar conditions,
the well-explored spiro-MeOTAD/Au based devices degraded
severely. In addition, we demonstrate that both spiro-MeOTAD
and bare TiO2 components are more susceptible to UV light.
Small 2019, 15, 1904746
Consequently, we made an unprecedented move and explored
atomic layer deposition tool to deposit thin and conformal
amorphous oxide layer onto mesoporous photoanode to further
mitigate the catastrophic effects induced by ultraviolet light. In
summary, our work demonstrates the development of efficient
and low-cost perovskite solar cells, which are not merely stable
under operational conditions but also under UV light thus
holding great potential for the commercial application of this
photovoltaic technology.
Supporting Information
Supporting Information is available from the Wiley Online Library or
from the author.
Acknowledgements
N.A. and M.I.D. contributed equally to this work. N.A. gratefully
acknowledges financial support from Greatcell Solar SA. M.I.D.
acknowledges the financial support from the Swiss National Science
Foundation under the Project No. P300P2_174471. S.A. thanks TUBITAK
– 2214-A International Doctoral Research Fellowship Programme, for
supporting his researches at EPFL. Y.L., T.B., S.M.Z., and M.G. thank the
King Abdulaziz City for Science and Technology (KACST) and the SNSF
for the project under JST-SNSF program (Grant No. IZJSZ2_180176), for
financial support. The authors would like to thank Dr. Richard Gaal,
EPFL for his help with Raman measurement. M.I.D. and N.A. conceived
and designed the project. N.A., M.I.D., S.A., and R.U. fabricated solar
cells. N.A. and M.I.D. characterized the devices and performed the
stability measurements. T.B. and Y.L. contributed toward the device
fabrication. M.I.D. and N.A. recorded and discussed the TRPL, SEM, and
Raman data. M.I.D. and N.A. wrote the manuscript, and all the authors
contributed toward finalizing the draft. S.M.Z. contributed to data
analysis and helped with the coordination of the project. M.G. directed
and M.I.D. and M.G. supervised the research.
Conflict of Interest
The authors declare no conflict of interest.
Keywords
carbon, efficiency, inorganic hole conductor, perovskite solar cells,
stability
Received: August 22, 2019
Revised: September 22, 2019
Published online: October 31, 2019
[1] National Renewable Energy Laboratory (NREL), https://www.nrel.
gov/pv/assets/pdfs/best-research-cell-efficiencies.20190923.pdf
(accessed: August 2019).
[2] a) A. Kojima, K. Teshima, Y. Shirai, T. Miyasaka, J. Am. Chem.
Soc. 2009, 131, 6050. b) H.-S. Kim, C.-R. Lee, J.-H. Im, K.-B. Lee,
T. Moehl, A. Marchioro, S.-J. Moon, R. Humphry-Baker, J.-H. Yum,
J. E. Moser, M. Grätzel, N.-G. Park, Sci. Rep. 2012, 2, 591.
c) M. M. Lee, J. Teuscher, T. Miyasaka, T. N. Murakami, H. J. Snaith,
Science 2012, 338, 643.
1904746 (5 of 6)
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[3] a) Y. Liu, S. Akin, L. Pan, R. Uchida, N. Arora, J. V. Milić,
A. Hinderhofer, F. Schreiber, A. R. Uhl, S. M. Zakeeruddin,
A. Hagfeldt, M. I. Dar, M. Grätzel, Sci. Adv. 2019, 5, eaaw2543.
[4] Y. Wang, M. I. Dar, L. K. Ono, T. Y. Zhang, M. Kan, Y. W. Li,
L. J. Zhang, X. T. Wang, Y. G. Yang, X. Y. Gao, Y. B. Qi, M. Gratzel,
Y. X. Zhao, Science 2019, 365, 591.
[5] a) S. Sun, T. Salim, N. Mathews, M. Duchamp, C. Boothroyd,
G. Xing, T. C. Sum, Y. M. Lam, Energy Environ. Sci. 2014, 7, 399.
b) R. Uchida, S. Binet, N. Arora, G. Jacopin, M. H. Alotaibi,
A. Taubert, S. M. Zakeeruddin, M. I. Dar, M. Graetzel, Small 2018,
14, 1802033.
[6] D. Shi, V. Adinolfi, R. Comin, M. Yuan, E. Alarousu, A. Buin, Y. Chen,
S. Hoogland, A. Rothenberger, K. Katsiev, Y. Losovyj, X. Zhang,
P. A. Dowben, O. F. Mohammed, E. H. Sargent, O. M. Bakr, Science
2015, 347, 519.
[7] Q. Dong, Y. Fang, Y. Shao, P. Mulligan, J. Qiu, L. Cao, J. Huang,
Science 2015, 347, 967.
[8] a) S. D. Stranks, G. E. Eperon, G. Grancini, C. Menelaou,
M. J. P. Alcocer, T. Leijtens, L. M. Herz, A. Petrozza, H. J. Snaith,
Science 2013, 342, 341; b) M. I. Dar, G. Jacopin, S. Meloni,
A. Mattoni, N. Arora, A. Boziki, S. M. Zakeeruddin, U. Rothlisberger,
M. Grätzel, Sci Adv 2016, 2, e1601156;
[9] G. Xing, N. Mathews, S. Sun, S. S. Lim, Y. M. Lam, M. Grätzel,
S. Mhaisalkar, T. C. Sum, Science 2013, 342, 344.
[10] a) D. Bi, C. Yi, J. Luo, J.-D. Décoppet, F. Zhang, S. M. Zakeeruddin,
X. Li, A. Hagfeldt, M. Grätzel, Nat. Energy 2016, 1, 16142.
b) M. Abdi-Jalebi, M. Ibrahim Dar, S. P. Senanayak, A. Sadhanala,
Z. Andaji-Garmaroudi, L. M. Pazos-Outón, J. M. Richter,
A. J. Pearson, H. Sirringhaus, M. Grätzel, R. H. Friend, Sci. Adv.
2019, 5, eaav2012.
[11] W. S. Yang, B.-W. Park, E. H. Jung, N. J. Jeon, Y. C. Kim, D. U. Lee,
S. S. Shin, J. Seo, E. K. Kim, J. H. Noh, S. I. Seok, Science 2017, 356,
1376.
[12] Z. Song, C. L. McElvany, A. B. Phillips, I. Celik, P. W. Krantz,
S. C. Watthage, G. K. Liyanage, D. Apul, M. J. Heben, Energy
Environ. Sci. 2017, 10, 1297.
[13] a) J. Zhao, X. Zheng, Y. Deng, T. Li, Y. Shao, A. Gruverman, J. Shield,
J. Huang, Energy Environ. Sci. 2016, 9, 3650. b) S. Akin, Y. H. Liu,
M. I. Dar, S. M. Zakeeruddin, M. Gratzel, S. Turan, S. Sonmezoglu,
J. Mater. Chem. A 2018, 6, 20327. c) J. V. Milic, N. Arora, M. I. Dar,
S. M. Zakeeruddin, M. Gratzel, Adv. Mater. Interfaces 2018, 5, 1800416.
[14] a) N. Arora, M. I. Dar, A. Hinderhofer, N. Pellet, F. Schreiber,
S. M. Zakeeruddin, M. Grätzel, Science 2017, 358, 768. b) L. Kavan,
Z. V. Živcová, P. Hubík, N. Arora, M. I. Dar, S. M. Zakeeruddin,
M. Grätzel, ACS Appl. Energy Mater. 2019, 2, 4264.
[15] a) Z. Ku, Y. Rong, M. Xu, T. Liu, H. Han, Sci. Rep. 2013, 3, 3132.
b) A. K. Baranwal, H. Kanda, N. Shibayama, H. Masutani,
T. A. N. Peiris, S. Kanaya, H. Segawa, T. Miyasaka, S. Ito, Energy
Technol. 2019, 7, 245.
[16] Y. Rong, X. Hou, Y. Hu, A. Mei, L. Liu, P. Wang, H. Han, Nat.
Commun. 2017, 8, 14555.
[17] X. Zheng, H. Chen, Q. Li, Y. Yang, Z. Wei, Y. Bai, Y. Qiu, D. Zhou,
K. S. Wong, S. Yang, Nano Lett. 2017, 17, 2496.
[18] a) S. Liu, W. Huang, P. Liao, N. Pootrakulchote, H. Li, J. Lu,
J. Li, F. Huang, X. Shai, X. Zhao, Y. Shen, Y.-B. Cheng, M. Wang,
J. Mater. Chem. A 2017, 5, 22952. b) S. G. Hashmi, D. Martineau,
M. I. Dar, T. T. T. Myllymäki, T. Sarikka, V. Ulla, S. M. Zakeeruddin,
M. Grätzel, J. Mater. Chem. A 2017, 5, 12060. c) S. G. Hashmi,
D. Martineau, X. Li, M. Ozkan, A. Tiihonen, M. I. Dar, T. Sarikka,
S. M. Zakeeruddin, J. Paltakari, P. D. Lund, M. Grätzel, Adv. Mater.
Technol. 2017, 2, 1600183.
[19] K. Aitola, K. Domanski, J.-P. Correa-Baena, K. Sveinbjörnsson,
M. Saliba, A. Abate, M. Grätzel, Adv. Mater. 2017, 29, 1606398.
[20] F. Lang, M. A. Gluba, S. Albrecht, J. Rappich, L. Korte, B. Rech,
N. H. Nickel, J. Phys. Chem. Lett. 2015, 6, 2745.
Small 2019, 15, 1904746
[21] P. You, Z. Liu, Q. Tai, S. Liu, F. Yan, Adv. Mater. 2015, 27, 3632.
[22] A. K. Baranwal, H. Kanda, N. Shibayama, S. Ito, Sustainable Energy
Fuels 2018, 2, 2778.
[23] Y. Lv, Y. Guo, H. Zhang, X. Zhou, H. Chen, Sol. Energy 2018, 173, 7.
[24] A. Mei, X. Li, L. Liu, Z. Ku, T. Liu, Y. Rong, M. Xu, M. Hu, J. Chen,
Y. Yang, M. Grätzel, H. Han, Science 2014, 345, 295.
[25] A. C. Ferrari, J. C. Meyer, V. Scardaci, C. Casiraghi, M. Lazzeri,
F. Mauri, S. Piscanec, D. Jiang, K. S. Novoselov, S. Roth,
A. K. Geim, Phys. Rev. Lett. 2006, 97, 187401.
[26] a) N. Marinova, W. Tress, R. Humphry-Baker, M. I. Dar, V. Bojinov,
S. M. Zakeeruddin, M. K. Nazeeruddin, M. Grätzel, ACS Nano
2015, 9, 4200. b) A. Greco, A. Hinderhofer, M. I. Dar, N. Arora,
J. Hagenlocher, A. Chumakov, M. Grätzel, F. Schreiber, J. Phys.
Chem. Lett. 2018, 9, 6750.
[27] M. Abdi-Jalebi, Z. Andaji-Garmaroudi, S. Cacovich, C. Stavrakas,
B. Philippe, J. M. Richter, M. Alsari, E. P. Booker, E. M. Hutter,
A. J. Pearson, S. Lilliu, T. J. Savenije, H. Rensmo, G. Divitini,
C. Ducati, R. H. Friend, S. D. Stranks, Nature 2018, 555, 497.
[28] H. J. Snaith, A. Abate, J. M. Ball, G. E. Eperon, T. Leijtens,
N. K. Noel, S. D. Stranks, J. T.-W. Wang, K. Wojciechowski,
W. Zhang, J. Phys. Chem. Lett. 2014, 5, 1511.
[29] a) X. Liu, Z. Liu, B. Sun, X. Tan, H. Ye, Y. Tu, T. Shi, Z. Tang,
G. Liao, Nano Energy 2018, 50, 201. b) E. A. Alharbi, M.
I. Dar, N. Arora, M. Alotaibi, Y. A. Alzhrani, P. Yadav, W. Tress,
A. Alyamani, A. Albadri, S. M. Zakeeruddin, M. Grätzel, Research
2019, 2019, 8474698. c) M. H. Alotaibi, Y. A. Alzahrani, N. Arora,
A. Alyamani, A. Albadri, H. Albrithen, I. H. Al-Lehyani, S. M. Alenzi,
A. Z. Alanzi, F. S. Alghamdi, S. M. Zakeeruddin, S. Meloni,
M. I. Dar, M. Graetzel, Sol. RRL 2019, 1900234, https://doi.
org/10.1002/solr.201900234.
[30] M. I. Saidaminov, J. Kim, A. Jain, R. Quintero-Bermudez, H. Tan,
G. Long, F. Tan, A. Johnston, Y. Zhao, O. Voznyy, E. H. Sargent,
Nat. Energy 2018, 3, 648.
[31] J. Chen, J.-Y. Seo, N.-G. Park, Adv. Energy Mater. 2018, 8, 1702714.
[32] J. Liu, Y. Wu, C. Qin, X. Yang, T. Yasuda, A. Islam, K. Zhang,
W. Peng, W. Chen, L. Han, Energy Environ. Sci. 2014, 7, 2963.
[33] T. Leijtens, G. E. Eperon, S. Pathak, A. Abate, M. M. Lee,
H. J. Snaith, Nat. Commun. 2013, 4, 2885.
[34] S. S. Shin, E. J. Yeom, W. S. Yang, S. Hur, M. G. Kim, J. Im, J. Seo,
J. H. Noh, S. I. Seok, Science 2017, 356, 167.
[35] S.-W. Lee, S. Kim, S. Bae, K. Cho, T. Chung, L. E. Mundt, S. Lee,
S. Park, H. Park, M. C. Schubert, S. W. Glunz, Y. Ko, Y. Jun, Y. Kang,
H.-S. Lee, D. Kim, Sci. Rep. 2016, 6, 38150.
[36] W. Li, W. Zhang, S. Van Reenen, R. J. Sutton, J. Fan,
A. A. Haghighirad, M. B. Johnston, L. Wang, H. J. Snaith, Energy
Environ. Sci. 2016, 9, 490.
[37] a) L. Kavan, L. Steier, M. Grätzel, J. Phys. Chem. C 2017, 121, 342.
b) J. P. Correa Baena, L. Steier, W. Tress, M. Saliba, S. Neutzner,
T. Matsui, F. Giordano, T. J. Jacobsson, A. R. Srimath Kandada,
S. M. Zakeeruddin, A. Petrozza, A. Abate, M. K. Nazeeruddin,
M. Grätzel, A. Hagfeldt, Energy Environ. Sci. 2015, 8, 2928.
[38] A. K. Chandiran, M. Abdi-Jalebi, A. Yella, M. I. Dar, C. Yi,
S. A. Shivashankar, M. K. Nazeeruddin, M. Grätzel, Nano Lett.
2014, 14, 1190.
[39] J. A. Christians, P. Schulz, J. S. Tinkham, T. H. Schloemer,
S. P. Harvey, B. J. Tremolet de Villers, A. Sellinger, J. J. Berry,
J. M. Luther, Nat. Energy 2018, 3, 68.
[40] H. J. Snaith, P. Hacke, Nat. Energy 2018, 3, 459.
[41] J. You, L. Meng, T.-B. Song, T.-F. Guo, Y. Yang, W.-H. Chang,
Z. Hong, H. Chen, H. Zhou, Q. Chen, Y. Liu, N. De Marco, Y. Yang,
Nat. Nanotechnol. 2016, 11, 75.
[42] W. Chen, Y. Wu, Y. Yue, J. Liu, W. Zhang, X. Yang, H. Chen, E. Bi,
I. Ashraful, M. Grätzel, L. Han, Science 2015, 350, 944.
[43] F. Bella, G. Griffini, J.-P. Correa-Baena, G. Saracco, M. Grätzel,
A. Hagfeldt, S. Turri, C. Gerbaldi, Science 2016, 354, 203.
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