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http://dx.doi.org/10.1007/s13391-018-0073-7

Low-Temperature Processable Charge Transporting Materials for the Flexible Perovskite Solar Cells  

Jo, Jea Woong (Department of Energy and Materials Engineering, Dongguk University)
Yoo, Yongseok (Department of Chemical Engineering, Hanyang University)
Jeong, Taehee (Department of Chemical Engineering, Hanyang University)
Ahn, SeJin (Photovoltaics Laboratory, Korea Institute of Energy Research (KIER))
Ko, Min Jae (Department of Chemical Engineering, Hanyang University)
Publication Information
Electronic Materials Letters / v.14, no.6, 2018 , pp. 657-668 More about this Journal
Abstract
Organic-inorganic hybrid lead halide perovskites have been extensively investigated for various optoelectronic applications. Particularly, owing to their ability to form highly crystalline and homogeneous films utilizing low-temperature solution processes (< $150^{\circ}C$), perovskites have become promising photoactive materials for realizing high-performance flexible solar cells. However, the current use of mesoporous $TiO_2$ scaff olds, which require high-temperature sintering processes (> $400^{\circ}C$), has limited the fabrication of perovskite solar cells on flexible substrates. Therefore, the development of a low-temperature processable charge-transporting layer has emerged as an urgent task for achieving flexible perovskite solar cells. This review summarizes the recent progress in low-temperature processable electron- and hole-transporting layer materials, which contribute to improved device performance in flexible perovskite solar cells.
Keywords
Perovskite; Charge-transporting layer; Flexible electronics; Solar cells; Low-temperature process; Interface engineering;
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1 He, Q., Yao, K., Wang, X., Xia, X., Leng, S., Li, F. : Room-temperature and solution-processable Cu-doped nickel oxide nanoparticles for efficient hole-transport layers of flexible large-area perovskite solar cells. ACS Appl. Mater. Interfaces 9, 41887 (2017)   DOI
2 Wu, Y., Yang, X., Chen, H., Zhang, K., Qin, C., Liu, J., Peng, W., Islam, A., Bi, E., Ye, F., Yin, M., Zhang, P., Han, L. : Highly compact $TiO_2$ layer for efficient hole-blocking in perovskite solar cells. Appl. Phys. Express 7, 052301 (2014)   DOI
3 Saliba, M., Matsui, T., Domanski, K., Seo, J.-Y., Ummadisingu, A., Zakeeruddin, S.M., Correa-Baena, J.-P., Tress, W.R., Abate, A., Hagfeldt, A., Gratzel, M. : Incorporation of rubidium cations into perovskite solar cells improves photovoltaic performance. Science 354, 206 (2016)   DOI
4 Ke, W., Fang, G., Liu, Q., Xiong, L., Qin, P., Tao, H., Wang, J., Lei, H., Li, B., Wan, J., Yang, G., Yan, Y. : Low-temperature solution-processed tin oxide as an alternative electron transporting layer for efficient perovskite solar cells. J. Am. Chem. Soc. 137, 6730 (2015)   DOI
5 Baena, J.P.C., Steier, L., Tress, W., Saliba, M., Neutzner, S., Matsu, T., Giordano, F., Jacobsson, T.J., Kandada, A.R.S., Zakeeruddin, S.M., Petrozza, A., Abate, A., Nazeeruddin, M.K., Gratzel, M., Hagfeldt, A. : Highly efficient planar perovskite solar cells through band alignment engineering. Energy Environ. Sci. 8, 2928 (2015)   DOI
6 Jiang, Q., Zhang, L., Wang, H., Yang, X., Meng, J., Liu, H., Yin, Z., Wu, J., Zhang, X., You, J. : Enhanced electron extraction using $SnO_2$ for high-efficiency planar-structure $HC(NH_2)_2PbI_3$ -based perovskite solar cells. Nat. Energy 2, 16177 (2016)
7 Kang, J.S., Kim, J.-Y., Yoon, J., Kim, J., Yang, J., Chung, D.Y., Kim, M., Jeong, H., Son, Y.J., Kim, B.G., Jeong, J., Hyeon, T., Choi, M., Ko, M.J., Sung, Y.-E. : Room-temperature vapor deposition of cobalt nitride nanofilms for mesoscopic and perovskite solar cells. Adv. Energy Mater. 8, 1703114 (2018)   DOI
8 Zhang, Y., Hu, X., Chen, L., Huang, Z., Fu, Q., Liu, Y., Zhang, L., Chen, Y. : Flexible, hole transporting layer-free and stable $CH_3NH_3PbI_3/PC_{61}$BM planar heterojunction perovskite solar cells. Org. Electron. 30, 281 (2016)   DOI
9 Guo, Y., Shoyama, K., Sato, W., Nakamura, E. : Polymer stabilization of lead(II) perovskite cubic nanocrystals for semitransparent solar cells. Adv. Energy Mater. 6, 1502317 (2016)   DOI
10 Bi, D., Yi, C., Luo, J., Decoppet, J.-D., Zhang, F., Zakeeruddin, S.M., Li, X., Hagfeldt, A., Gratzel, M. : Polymer-templated nucleation and crystal growth of perovskite films for solar cells with efficiency greater than 21%. Nat. Energy 1, 16142 (2016)   DOI
11 Wang, X., Lia, Z., Xu, W., Kulkarni, S.A., Batabyal, S.K., Zhang, S., Cao, A., Wong, L.H. : TiO2 nanotube arrays based flexible perovskite solar cells with transparent carbon nanotube electrode. Nano Energy 11, 728 (2015)   DOI
12 Nejand, B.A., Nazari, P., Gharibzadeh, S., Ahmadi, V., Moshaii, A. : All-inorganic large-area low-cost and durable flexible perovskite solar cells using copper foil as a substrate. Chem. Commun. 53, 747 (2017)   DOI
13 Stranks, S.D., Eperon, G.E., Grancini, G., Menelaou, C., Alcocer, M.J.P., Leijtens, T., Herz, L.M., Petrozza, A., Snaith, H.J. : Electron-hole diffusion lengths exceeding 1 micrometer in an organometal trihalide perovskite absorber. Science 342, 341 (2013)   DOI
14 Hu, X., Huang, Z., Zhou, X., Li, P., Wang, Y., Huang, Z., Su, M., Ren, W., Li, F., Li, M., Chen, Y., Song, Y. : Wearable largescale perovskite solar-power source via nanocellular scaffold. Adv. Mater. 29, 1703236 (2017)   DOI
15 Jeong, I., Kim, H.J., Lee, B.-S., Son, H.J., Kim, J.Y., Lee, D.-K., Kim, D.-E., Lee, J., Ko, M.J. : Highly efficient perovskite solar cells based on mechanically durable molybdenum cathode. Nano Energy 17, 131 (2015)   DOI
16 Docampo, P., Ball, J.M., Darwich, M., Eperon, G.E., Snaith, H.J. : Efficient organometal trihalide perovskite planar-heterojunction solar cells on flexible polymer substrates. Nat. Commun. 4, 2761 (2013)   DOI
17 You, J., Hong, Z., Yang, Y., Chen, Q., Cai, M., Song, T.-B., Chen, C.-C., Lu, S., Liu, Y., Zhou, H., Yang, Y. : Low-temperature solution-processed perovskite solar cells with high efficiency and flexibility. ACS Nano 8, 1674 (2014)   DOI
18 Lim, K.-G., Kim, H.-B., Jeong, J., Kim, H., Kim, J.Y., Lee, T.-W. : Boosting the power conversion efficiency of perovskite solar cells using self-organized polymeric hole extraction layers with high work function. Adv. Mater. 26, 6461 (2014)   DOI
19 Park, M., Kim, H.J., Jeong, I., Lee, J., Lee, H., Son, H.J., Kim, D.-E., Ko, M.J. : Mechanically recoverable and highly efficient perovskite solar cells: investigation of intrinsic flexibility of organic-inorganic perovskite. Adv. Energy Mater. 5, 1501406 (2015)   DOI
20 Jeon, N.J., Noh, J.H., Yang, W.S., Kim, Y.C., Ryu, S., Seo, J., Seok, S.I. : Compositional engineering of perovskite materials for high-performance solar cells. Nature 517, 476 (2015)   DOI
21 National Renewable Energy Laboratory, Best Research-Cell Efficiencies Chart. https://www.nrel.gov/pv/assets/images/efficiency-chart.png
22 Yang, D., Yang, R., Zhang, J., Yang, Z., Liu, S., Li, C. : High efficiency flexible perovskite solar cells using superior low temperature $TiO_2$. Energy Environ. Sci. 8, 3208 (2015)   DOI
23 Vclker, S.F., Collavini, S., Delgado, J.L. : Organic charge carriers for perovskite solar cells. ChemSusChem 8, 3012 (2015)   DOI
24 Shin, S.S., Yang, W.S., Yeom, E.J., Lee, S.J., Jeon, N.J., Joo, Y.-C., Park, I.J., Noh, J.H., Seok, S.I. : Tailoring of electron-collecting oxide nanoparticulate layer for flexible perovskite solar cells. J. Phys. Chem. Lett. 7, 1845 (2016)   DOI
25 Chueh, C.-C., Lia, C.-Z., Jen, A.K.-Y. : Recent progress and perspective in solution-processed Interfacial materials for efficient and stable polymer and organometal perovskite solar cells. Energy Environ. Sci. 8, 1160 (2015)   DOI
26 Momblona, C., Gil-Escrig, L., Bandiello, E., Hutter, E.M., Sessolo, M., Lederer, K., Blochwitz-Nimoth, J., Bolink, H.J. : Efficient vacuum deposited p-i-n and n-i-p perovskite solar cells employing doped charge transport layers. Energy Environ. Sci. 9, 3456 (2016)   DOI
27 Kim, B.J., Kim, D.H., Lee, Y.-Y., Shin, H.-W., Han, G.S., Hong, J.S., Mahmood, K., Ahn, T.K., Joo, Y.-C., Hong, K.S., Park, N.-G., Lee, S., Jung, H.S. : Highly efficient and bending durable perovskite solar cells: toward a wearable power source. Energy Environ. Sci. 8, 916 (2015)   DOI
28 Jeong, I., Jung, H., Park, M., Suh Park, J., Son, H.J., Joo, J., Lee, J., Ko, M.J. : A tailored $TiO_2$ electron selective layer for high-performance flexible perovskite solar cells via low temperature UV process. Nano Energy 28, 380 (2016)   DOI
29 Bi, C., Chen, B., Wei, H., DeLuca, S., Huang, J. : Efficient flexible solar cell based on composition-tailored hybrid perovskite. Adv. Mater. 29, 1605900 (2017)   DOI
30 Jo, J.W., Seo, M.-S., Park, M., Kim, J.-Y., Park, J.S., Han, I.K., Ahn, H., Jung, J.W., Sohn, B.-H., Ko, M.J., Son, H.J. : Improving performance and stability of flexible planar-heterojunction perovskite solar cells using polymeric hole-transport material. Adv. Funct. Mater. 26, 4464 (2016)   DOI
31 Yin, X., Chen, P., Que, M., Xing, Y., Que, W., Niu, C., Shao, J. : Highly efficient flexible perovskite solar cells using solution-derived $NiO_x$ hole contacts. ACS Nano 10, 3630 (2016)   DOI
32 Shao, Y., Yuan, Y., Huang, J. : Correlation of energy disorder and open-circuit voltage in hybrid perovskite solar cells. Nat. Energy 1, 15001 (2016)   DOI
33 Shin, S.S., Kim, D.W., Hwang, D., Suk, J.H., Oh, L.S., Han, B.S., Kim, D.H., Kim, J.S., Kim, D., Kim, J.Y., Hong, K.S. : Controlled interfacial electron dynamics in highly efficient $Zn_2SnO_4$-based dye-sensitized solar cells. ChemSusChem 7, 501 (2014)   DOI
34 Young, D.L., Moutinho, H., Yan, Y., Coutts, T.J. : Growth and characterization of radio frequency magnetron sputter-deposited zinc stannate, $Zn_2SnO_4$, thin films. J. Appl. Phys. 92, 310 (2002)   DOI
35 Shao, Y., Xiao, Z., Bi, C., Yuan, Y., Huang, J. : Origin and elimination of photocurrent hysteresis by fullerene passivation in $CH_3NH_3PbI_3$ planar heterojunction solar cells. Nat. Commun. 5, 5784 (2014)   DOI
36 Wolff, C.M., Zu, F., Paulke, A., Toro, L.P., Koch, N., Neher, D. : Reduced interface-mediated recombination for high open-circuit voltages in $CH_3NH_3PbI_3$ solar cells. Adv. Mater. 29, 1700159 (2017)   DOI
37 Na, S.-I., Wang, G., Kim, S.-S., Kim, T.-W., Oh, S.-H., Yu, B.-K., Lee, T., Kim, D.-Y. : Evolution of nanomorphology and anisotropic conductivity in solvent-modified PEDOT:PSS films for polymeric anodes of polymer solar cells. J. Mater. Chem. 19, 9045 (2009)   DOI
38 Hou, F., Su, Z., Jin, F., Yan, X., Wang, L., Zhao, H., Zhu, J., Chu, B., Lia, W. : Efficient and stable planar heterojunction perovskite solar cells with an $MoO_3$/PEDOT:PSS hole transporting layer. Nanoscale 7, 9427 (2015)   DOI
39 Wehrenfennig, C., Eperon, G.E., Johnston, M.B., Snaith, H.J., Herz, L.M. : High charge carrier mobilities and lifetimes in organolead trihalide perovskites. Adv. Mater. 26, 1584 (2014)   DOI
40 Leijtens, T., Stranks, S.D., Eperon, G.E., Lindblad, R., Johansson, E.M.J., McPherson, I.J., Rensmo, H., Ball, J.M., Lee, M.M., Snaith, H.J. : Electronic properties of meso-superstructured and planar organometal halide perovskite films: charge trapping, photodoping, and carrier mobility. ACS Nano 8, 7147 (2014)   DOI
41 Jung, J.W., Chueh, C.-C., Jen, A.K.-Y., Low-Temperature, A. : Solution-processable, Cu-doped nickel oxide hole-transporting layer via the combustion method for high-performance thin-film perovskite solar cells. Adv. Mater. 27, 7874 (2015)   DOI
42 Hou, Y., Zhang, H., Chen, W., Chen, S., Quiroz, C.O.R., Azimi, H., Osvet, A., Matt, G.J., Zeira, E., Seuring, J., Kausch-Busies, N., Lovenich, W., Brabec, C.J. : Inverted, environmentally stable perovskite solar cell with a novel low-cost and water-free PEDOT hole-extraction layer. Adv. Energy Mater. 5, 1500543 (2015)   DOI
43 D'Innocenzo, V., Grancini, G., Alcocer, M.J.P., Kandada, A.R.S., Stranks, S.D., Lee, M.M., Lanzani, G., Snaith, H.J., Petrozza, A. : Excitons versus free charges in organo-lead tri-halide perovskites. Nat. Commun. 5, 3586 (2014)   DOI
44 Kojima, A., Teshima, K., Shirai, Y., Miyasaka, T. : Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. J. Am. Chem. Soc. 131, 6050 (2009)   DOI
45 Zhu, Z., Bai, Y., Zhang, T., Liu, Z., Long, X., Wei, Z., Wang, Z., Zhang, L., Wang, J., Yan, F., Yang, S. : High-performance hole-extraction layer of sol-gel-processed NiO nanocrystals for inverted planar perovskite solar cells. Angew. Chem. Int. Ed. 53, 12571 (2014)
46 Kim, J.H., Liang, P.W., Williams, S.T., Cho, N., Chueh, C.C., Glaz, M.S., Ginger, D.S., Jen, A.K.-Y. : High-performance and environmentally stable planar heterojunction perovskite solar cells based on a solution-processed copper-doped nickel oxide hole-transporting layer. Adv. Mater. 27, 695 (2015)   DOI
47 Green, M., Ho-Baillie, A., Snaith, H.J. : The emergence of perovskite solar cells. Nat. Photonics 8, 506 (2014)   DOI
48 Hwang, K., Jung, Y.-S., Heo, Y.-J., Scholes, F.H., Watkins, S.E., Subbiah, J., Jones, D.J., Kim, D.-Y., Vak, D. : Toward large scale roll-to-roll production of fully printed perovskite solar cells. Adv. Mater. 27, 1241 (2015)   DOI
49 Yang, W.S., Park, B.-W., Jung, E.H., Jeon, N.J., Kim, Y.C., Lee, D.U., Shin, S.S., Seo, J., Kim, E.K., Noh, J.H., Seok, S.I. : Iodide management in formamidinium-lead-halide-based perovskite layers for efficient solar cells. Science 356, 1376 (2017)   DOI
50 McMeekin, D.P., Sadoughi, G., Rehman, W., Eperon, G.E., Saliba, M., Horantner, M.T., Haghighirad, A., Sakai, N., Korte, L., Rech, B., Johnston, M.B., Herz, L.M., Snaith, H.J. : A mixed-cation lead mixed-halide perovskite absorber for tandem solar cells. Science 351, 151 (2016)   DOI
51 Bae, S., Han, S.J., Shin, T.J., Jo, W.H. : Two different mechanisms of $CH_3NH_3PbI_3$ film formation in one-step deposition and its effect on photovoltaic properties of OPV-type perovskite solar cells. J. Mater. Chem. 3, 23964 (2015)   DOI
52 Mali, S.S., Hong, C.K. : p-i-n/n-i-p type planar hybrid structure of highly efficient perovskite solar cells towards improved air stability: synthetic strategies and the role of p-type hole transport layer (HTL) and n-type electron transport layer (ETL) metal oxides. Nanoscale 8, 10528 (2016)   DOI
53 Nguyen, W.H., Bailie, C.D., Unger, E.L., McGehee, M.D. : Enhancing the hole-conductivity of spiro-OMeTAD without oxygen or lithium salts by using spiro $(TFSI)_2$ in perovskite and dye-sensitized solar cells. J. Am. Chem. Soc. 136, 10996 (2014)   DOI
54 Wang, Q.-K., Wang, R.-B., Shen, P.-F., Li, C., Li, Y.-Q., Liu, L.-J., Duhm, S., Tang, J.-X. : Energy level off sets at lead halide perovskite/organic hybrid interfaces and their impacts on charge separation. Adv. Mater. Interfaces 2, 1400528 (2015)   DOI
55 Shin, S.S., Yang, W.S., Noh, J.H., Suk, J.H., Jeon, N.J., Park, J.H., Kim, J.S., Seong, W.M., Seok, S.I. : High-performance flexible perovskite solar cells exploiting $Zn_2SnO_4$ prepared in solution below $100^{\circ}C$. Nat. Commun. 6, 7410 (2015)   DOI
56 Kumar, M.H., Yantara, N., Dharani, S., Graetzel, M., Mhaisalkar, S., Boix, P.P., Mathews, N. : Flexible, low-temperature, solution processed ZnO-based perovskite solid state solar cells. Chem. Commun. 49, 11089 (2013)   DOI
57 Liu, D., Kelly, T.L. : Perovskite solar cells with a planar heterojunction structure prepared using room-temperature solution processing techniques. Nat. Photonics 8, 133 (2013)
58 Park, M., Kim, J.-Y., Son, H.J., Lee, C.-H., Jang, S.S., Ko, M.J. : Low-temperature solution-processed Li-doped $SnO_2$ as an effective electron transporting layer for high-performance flexible and wearable perovskite solar cells. Nano Energy 26, 208 (2016)   DOI
59 Saliba, M., Matsui, T., Seo, J.-Y., Domanski, K., Correa-Baena, J.-P., Nazeeruddin, M.K., Zakeeruddin, S.M., Tress, W., Abate, A., Hagfeldt, A., Gratzel, M. : Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency. Energy Environ. Sci. 9, 1989 (2016)   DOI
60 Seo, M.-S., Jeong, I., Park, J.-S., Lee, J., Han, I.K., Lee, W.I., Son, H.J., Sohn, B.-H., Ko, M.J. : Vertically aligned nanostructured $TiO_2$ photoelectrodes for high efficiency perovskite solar cells via a block copolymer template approach. Nanoscale 8, 11472 (2016)   DOI
61 Jeong, I., Park, Y.H., Bae, S., Park, M., Jeong, H., Lee, P., Ko, M.J. : Solution-processed ultrathin $TiO_2$ compact layer hybridized with mesoporous $TiO_2$ for high-performance perovskite solar cells. ACS Appl. Mater. Interfaces 9, 36865 (2017)   DOI
62 Azmi, R., Hadmojo, W.T., Sinaga, S., Lee, C.-L., Yoon, S.C., Jung, I.H., Jang, S.-Y. : Perovskite solar cells: high-efficiency lowtemperature ZnO based perovskite solar cells based on highly polar, nonwetting self-assembled molecular layers. Adv. Energy Mater. 8, 1701683 (2018)   DOI
63 Jeng, J.-Y., Chen, K.-C., Chiang, T.-Y., Lin, P.-Y., Tsai, T.-D., Chang, Y.-C., Guo, T.-F., Chen, P., Wen, T.-C., Hsu, Y.-J. : Nickel oxide electrode interlayer in $CH_3NH_3PbI_3$ perovskite/PCBM planar-heterojunction hybrid solar cells. Adv. Mater. 24, 4107 (2014)
64 Choi, J., Song, S., Horantner, M.T., Snaith, H.J., Park, T. : Well-defined nanostructured, single-crystalline $TiO_2$ electron transport layer for efficient planar perovskite solar cells. ACS Nano 10, 6029 (2016)   DOI
65 Chakravarthi, N., Gunasekar, K., Cho, W., Long, D.X., Kim, Y.-H., Song, C.E., Lee, J.-C., Facchetti, A., Song, M., Noh, Y.-Y., Jin, S.-H. : A simple structured and efficient triazine-based molecule as an interfacial layer for high performance organic electronics. Energy Environ. Sci. 9, 2595 (2016)   DOI
66 Huang, X., Wang, K., Yi, C., Meng, T., Gong, X. : Efficient perovskite hybrid solar cells by highly electrical conductive PEDOT:PSS hole transport layer. Adv. Energy Mater. 6, 1501773 (2016)   DOI
67 Kim, H.S., Lee, C.R., Im, J.H., Lee, K.B., Moehl, T., Marchioro, A., Moon, S.J., Humphry-Baker, R., Yum, J.H., Moser, J.E., Gratzel, M., Park, N.G. : Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Sci. Rep. 2, 591 (2012)   DOI
68 Cho, H., Jeong, S.-H., Park, M.-H., Kim, Y.-H., Wolf, C., Lee, C.-L., Heo, J.H., Sadhanala, A., Myoung, N., Yoo, S., Im, S.H., Friend, R.H., Lee, T.-W. : Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science 350, 1222 (2015)   DOI
69 Kranthiraja, K., Gunasekar, K., Kim, H., Cho, A.-N., Park, N.-G., Kim, S., Kim, B.J., Nishikubo, R., Saeki, A., Song, M., Jin, S.-H. : High-performance long-term-stable dopant-free perovskite solar cells and additive-free organic solar cells by employing newly designed multirole ${\pi}$-conjugated polymers. Adv. Mater. 29, 1700183 (2017)   DOI
70 Yana, W., Li, Y., Li, Y., Ye, S., Liu, Z., Wang, S., Bian, Z., Huang, C. : High-performance hybrid perovskite solar cells with open circuit voltage dependence on hole-transporting materials. Nano Energy 16, 428 (2015)   DOI
71 Noel, N.K., Stranks, S.D., Abate, A., Wehrenfennig, C., Guarnera, S., Haghighirad, A.-A., Sadhanala, A., Eperon, G.E., Pathak, S.K., Johnston, M.B., Petrozza, A., Herz, L.M., Snaith, H.J. : Lead-free organic-inorganic tin halide perovskites for photovoltaic applications. Energy Environ. Sci. 7, 3061 (2014)   DOI
72 Yuan, M., Quan, L.N., Comin, R., Walters, G., Sabatini, R., Voznyy, O., Hoogland, S., Zhao, Y., Beauregard, E.M., Kanjanaboos, P., Lu, Z., Kim, D.H., Sargent, E.H. : Perovskite energy funnels for efficient light-emitting diodes. Nat. Nanotechnol. 11, 872 (2016)   DOI
73 Dou, L., Yang, Y., You, J., Hong, Z., Chang, W.-H., Li, G., Yang, Y. : Solution-processed hybrid perovskite photodetectors with high detectivity. Nat. Commun. 5, 5404 (2014)   DOI
74 Hao, F., Stoumpos, C.C., Cao, D.H., Chang, R.P.H., Kanatzidis, M.G. : Lead-free solid-state organic-inorganic halide perovskite solar cells. Nat. Photonics 8, 489 (2014)   DOI
75 Xing, G., Mathews, N., Sun, S., Lim, S.S., Lam, Y.M., Gratzel, M., Mhaisalkar, S., Sum, T.C. : Long-range balanced electron- and hole-transport lengths in organic-inorganic $CH_3NH_3PbI_3$. Science 342, 344 (2013)   DOI
76 Hodes, G., Cahen, D. : Photovoltaics: Perovskite cells roll forward. Nat. Photonics 8, 87 (2014)   DOI
77 Feng, J., Yang, Z., Yang, D., Ren, X., Zhu, X., Jin, Z., Zi, W., Wei, Q., Liu, S. : E-beam evaporated $Nb_2O_5$ as an effective electron transport layer for large flexible perovskite solar cells. Nano Energy 36, 1 (2017)   DOI
78 Son, D.-Y., Lee, J.-W., Choi, Y.J., Jang, I.-H., Lee, S., Yoo, P.J., Shin, H., Ahn, N., Choi, M., Kim, D., Park, N.-G. : Self-formed grain boundary healing layer for highly efficient $CH_3NH_3PbI_3$ perovskite solar cells. Nat. Energy 1, 16081 (2016)   DOI
79 Lu, H., Ma, Y., Gu, B., Tian, W., Li, L. : Identifying the optimum thickness of electron transport layers for highly efficient perovskite planar solar cells. J. Mater. Chem. A 3, 16445 (2015)   DOI
80 Wang, K., Shia, Y., Gao, L., Chia, R., Shia, K., Guoa, B., Zhao, L., Ma, T. : $W(Nb)O_x$-based efficient flexible perovskite solar cells: from material optimization to working principle. Nano Energy 31, 424 (2017)   DOI
81 Ahn, N., Kwak, K., Jang, M.S., Yoon, H., Lee, B.Y., Lee, J.-K., Pikhitsa, P.V., Byun, J., Choi, M. : Trapped charge-driven degradation of perovskite solar cells. Nat. Commun. 7, 13422 (2016)   DOI
82 Ye, F., Tang, W., Xie, F., Yin, M., He, J., Wang, Y., Chen, H., Qiang, Y., Yang, X., Han, L. : Low-temperature soft-cover deposition of uniform large-scale perovskite films for high-performance solar cells. Adv. Mater. 29, 1701440 (2017)   DOI
83 Najafi, M., Giacomo, F.D., Zhang, D., Shanmugam, S., Senes, A., Verhees, W., Hadipour, A., Galagan, Y., Aernouts, T., Veenstra, S., Andriessen, R. : Highly efficient and stable flexible perovskite solar cells with metal oxides nanoparticle charge extraction layers. Small 14, 1702775 (2018)   DOI
84 Qiu, L., He, S., Yang, J., Deng, J., Peng, H. : Fiber-shaped perovskite solar cells with high power conversion efficiency. Small 12, 2419 (2016)   DOI
85 Liang, P.-W., Chueh, C.-C., Williams, S.T., Jen, A.K.-Y. : Roles of fullerene-based interlayers in enhancing the performance of organometal perovskite thin-film solar cells. Adv. Energy Mater. 5, 1402321 (2015)   DOI
86 Zuo, C., Ding, L. : Modified PEDOT layer makes a 1.52 $V_{oc}$ for perovskite/PCBM solar cells. Adv. Energy Mater. 7, 1601193 (2017)   DOI
87 Sin, D.H., Ko, H., Jo, S.B., Kim, M., Bae, G.Y., Cho, K. : Decoupling charge transfer and transport at polymeric hole transport layer in perovskite solar cells. ACS Appl. Mater. Interfaces 8, 6546 (2016)   DOI
88 Di Giacomo, F., Fakharuddin, A., Josec, R., Brown, T.M. : Progress, challenges and perspectives in flexible perovskite solar cells. Energy Environ. Sci. 9, 3007 (2016)   DOI
89 Popoola, I.K., Gondal, M.A., Qahtan, T.F. : Recent progress in flexible perovskite solar cells: materials, mechanical tolerance and stability. Renew. Sustain. Energy Rev. 82, 3127 (2018)   DOI
90 Nardes, A.M., Kemerink, M., Janssen, R.A.J., Bastiaansen, J.A.M., Kiggen, N.M.M., Langeveld, B.M.W., van Breemen, A.J.J.M., de Kok, M.M. : Microscopic understanding of the anisotropic conductivity of PEDOT:PSS thin films. Adv. Mater. 19, 1196 (2007)   DOI
91 Xu, X., Chen, Q., Hong, Z., Zhou, H., Liu, Z., Chang, W.-H., Sun, P., Chen, H., Marco, N.D., Wang, M., Yang, Y. : Working mechanism for flexible perovskite solar cells with simplified architecture. Nano Lett. 15, 6514 (2015)   DOI
92 Park, J.H., Seo, J., Park, S., Shin, S.S., Kim, Y.C., Jeon, N.J., Shin, H.-W., Ahn, T.K., Noh, J.H., Yoon, S.C., Hwang, C.S., Seok, S.I. : Efficient $CH_3NH_3PbI_3$ perovskite solar cells employing nanostructured p-type NiO electrode formed by a pulsed laser deposition. Adv. Mater. 27, 4013 (2015)   DOI
93 Jokar, E., Huang, Z.Y., Narra, S., Wang, C.-Y., Kattoor, V., Chung, C.-C., Diau, E.W.-G. : Anomalous charge-extraction behavior for graphene-oxide (GO) and reduced graphene-oxide (rGO) films as efficient p-contact layers for high-performance perovskite solar cells. Adv. Energy Mater. 8, 1701640 (2018)   DOI
94 Schmidt, T.M., Larsen-Olsen, T.T., Carle, J.E., Angmo, D., Krebs, F.C. : Upscaling of perovskite solar cells: fully ambient roll processing of flexible perovskite solar cells with printed back electrodes. Adv. Energy Mater. 5, 1500569 (2015)   DOI
95 Susrutha, B., Giribabuab, L., Singh, S.P. : Recent advances in flexible perovskite solar cells. Chem. Commun. 51, 14696 (2015)   DOI
96 Zhou, Y., Game, O.S., Pang, S., Padture, N.P. : Microstructures of organometal trihalide perovskites for solar cells: their evolution from solutions and characterization. J. Phys. Chem. Lett. 6, 4827 (2015)   DOI
97 Ahn, N., Son, D.-Y., Jang, I.-H., Kang, S.M., Choi, M., Park, N.-G. : Highly reproducible perovskite solar cells with average efficiency of 18.3% and best efficiency of 19.7% fabricated via lewis base adduct of lead(II) iodide. J. Am. Chem. Soc. 137, 8696 (2015)   DOI
98 Yoon, H., Kang, S.M., Lee, J.-K., Choi, M. : Hysteresis-free low-temperature-processed planar perovskite solar cells with 19.1% efficiency. Energy Environ. Sci. 9, 2262 (2016)   DOI
99 Wang, Y.-C., Li, X., Zhu, L., Liu, X., Zhang, W., Fang, J. : Efficient and hysteresis-free perovskite solar cells based on a solution processable polar fullerene electron transport layer. Adv. Energy Mater. 7, 1701144 (2017)   DOI
100 Jeng, J.-Y., Chiang, Y.-F., Lee, M.-H., Peng, S.-R., Guo, T.-F., Chen, P., Wen, T.-C. : $CH_3NH_3PbI_3$ perovskite/fullerene planarheterojunction hybrid solar cells. Adv. Mater. 25, 3727 (2013)   DOI
101 Heo, J.H., Im, S.H., Noh, J.H., Mandal, T.N., Lim, C.-S., Chang, J.A., Lee, Y.H., Kim, H.-J., Sarkar, A., Nazeeruddin, M.K., Gratzel, M., Seok, S.I. : Efficient inorganic-organic hybrid heterojunction solar cells containing perovskite compound and polymeric hole conductors. Nat. Photonics 7, 486 (2013)   DOI
102 Li, Y., Zhao, Y., Chen, Q., Yang, Y., Liu, Y., Hong, Z., Liu, Z., Hsieh, Y.-T., Meng, L., Li, Y., Yang, Y. : Multifunctional fullerene derivative for interface engineering in perovskite solar cells. J. Am. Chem. Soc. 137, 15540 (2015)   DOI
103 Lee, M.M., Teuscher, J., Miyasaka, T., Murakami, T.N., Snaith, H.J. : Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 338, 643 (2012)   DOI
104 Burschka, J., Pellet, N., Moon, S.J., Humphry-Baker, R., Gao, P., Nazeeruddin, M.K., Gratzel, M. : Sequential deposition as a route to high-performance perovskite-sensitized solar cells. Nature 499, 316 (2013)   DOI
105 Jeon, N.J., Noh, J.H., Kim, Y.C., Yang, W.S., Ryu, S., Seok, S.I. : Solvent engineering for high-performance inorganic-organic hybrid perovskite solar cells. Nat. Mater. 13, 897 (2014)   DOI
106 Yang, G., Tao, H., Qin, P., Ke, W., Fang, G. : Recent progress in electron transport layers for efficient perovskite solar cells. J. Mater. Chem. A 4, 3970 (2016)   DOI
107 Zhou, H., Chen, Q., Li, G., Luo, S., Song, T., Duan, H.-S., Hong, Z., You, J., Liu, Y., Yang, Y. : Interface engineering of highly efficient perovskite solar cells. Science 345, 542 (2014)   DOI
108 Shi, J., Xu, X., Li, D., Meng, Q. : Interfaces in perovskite solar cells. Small 11, 2472 (2015)   DOI
109 Koo, B., Jung, H., Park, M., Kim, J.-Y., Son, H.J., Cho, J., Ko, M.J. : Pyrite-based bi-functional layer for long-term stability and high-performance of organo-lead halide perovskite solar cells. Adv. Funct. Mater. 26, 5400 (2016)   DOI
110 Wang, Q., Chueh, C.-C., Zhao, T., Cheng, J., Eslamian, M., Choy, W.C.H., Jen, A.K.-Y. : Effects of self-assembled monolayer modification of nickel oxide nanoparticles layer on the performance and application of inverted perovskite solar cells. ChemSusChem 10, 3794 (2017)   DOI