Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-10T11:40:11.837Z Has data issue: false hasContentIssue false

Structure formation and evolution in semiconductor films for perovskite and organic photovoltaics

Published online by Cambridge University Press:  21 March 2017

Andrew J. Pearson*
Affiliation:
Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
*
a) Address all correspondence to this author. e-mail: ap824@cam.ac.uk
Get access

Abstract

The research and development of novel photovoltaic technologies is going through a golden era, thanks to the demonstration of remarkable efficiencies across a broad range of semiconductor classes and device architectures. In parallel with these developments, the opportunities for characterizing the structure of a semiconductor film in situ of a processing step have also increased, to the extent that in situ and in operando experiments are becoming readily accessible to researchers. These combined advances represent the subject matter of this article, wherein studies that improve our understanding of structure formation and evolution in perovskite and organic semiconductor films for innovative solar cells are reviewed. Although focus is placed on the dynamics of semiconductor film formation, the review also highlights recent research on environmental testing, a key component in the development of materials with high intrinsic stability.

Type
Invited Review
Copyright
Copyright © Materials Research Society 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Contributing Editor: Dean DeLongchamp

This section of Journal of Materials Research is reserved for papers that are reviews of literature in a given area.

References

REFERENCES

Kerr, R.A.: Do we have the energy for the next transition? Science 329(5993), 780 (2010).Google Scholar
Cho, A.: Energy’s tricky tradeoffs. Science 329(5993), 786 (2010).Google Scholar
I.E. Agency: Technology Roadmap: Solar Photovoltaic Energy (2014 Edition), (2014).Google Scholar
Global Market Outlook for Photovoltaics 2014–2018 http://www.solarpowereurope.org/home/.Google Scholar
Polman, A., Knight, M., Garnett, E.C., Ehrler, B., and Sinke, W.C.: Photovoltaic materials: Present efficiencies and future challenges. Science 352(6283), aad4424 (2016).Google Scholar
Pearson, A.J., Wang, T., and Lidzey, D.G.: The role of dynamic measurements in correlating structure with optoelectronic properties in polymer:fullerene bulk-heterojunction solar cells. Rep. Prog. Phys. 76(2), 022501 (2013).Google Scholar
Li, G., Zhu, R., and Yang, Y.: Polymer solar cells. Nat. Photonics 6(3), 153 (2012).Google Scholar
Green, M.A., Ho-Baillie, A., and Snaith, H.J.: The emergence of perovskite solar cells. Nat. Photonics 8(7), 506 (2014).Google Scholar
Darling, S.B. and You, F.: The case for organic photovoltaics. RSC Adv. 3(39), 17633 (2013).Google Scholar
Gong, J., Darling, S.B., and You, F.: Perovskite photovoltaics: Life-cycle assessment of energy and environmental impacts. Energy Environ. Sci. 8(7), 1953 (2015).Google Scholar
Müller-Buschbaum, P.: The active layer morphology of organic solar cells probed with grazing incidence scattering techniques. Adv. Mater. 26(46), 7692 (2014).Google Scholar
Chen, W., Nikiforov, M.P., and Darling, S.B.: Morphology characterization in organic and hybrid solar cells. Energy Environ. Sci. 5(8), 8045 (2012).Google Scholar
Pazos-Outon, L.M., Szumilo, M., Lamboll, R., Richter, J.M., Crespo-Quesada, M., Abdi-Jalebi, M., Beeson, H.J., Vrućinić, M., Alsari, M., Snaith, H.J., Ehrler, B., Friend, R.H., and Deschler, F.: Photon recycling in lead iodide perovskite solar cells. Science 351(6280), 1430 (2016).Google Scholar
Brenner, T.M., Egger, D.A., Kronik, L., Hodes, G., and Cahen, D.: Hybrid organic–inorganic perovskites: Low-cost semiconductors with intriguing charge-transport properties. Nat. Rev. Mater. 1(1), 15007 (2016).Google Scholar
Sutherland, B.R. and Sargent, E.H.: Perovskite photonic sources. Nat. Photonics 10(5), 295 (2016).Google Scholar
Zhu, H., Miyata, K., Fu, Y., Wang, J., Joshi, P.P., Niesner, D., Williams, K.W., Jin, S., and Zhu, X.Y.: Screening in crystalline liquids protects energetic carriers in hybrid perovskites. Science 353(6306), 1409 (2016).Google Scholar
Zhang, W., Eperon, G.E., and Snaith, H.J.: Metal halide perovskites for energy applications. Nat. Energy 1(6), 16048 (2016).CrossRefGoogle Scholar
Stoumpos, C.C. and Kanatzidis, M.G.: Halide perovskites: Poor Man’s high-performance semiconductors. Adv. Mater. 28(28), 5778 (2016).Google Scholar
Stoumpos, C.C. and Kanatzidis, M.G.: The renaissance of halide perovskites and their evolution as emerging semiconductors. Acc. Chem. Res. 48(10), 2791 (2015).Google Scholar
Deng, Y., Peng, E., Shao, Y., Xiao, Z., Dong, Q., and Huang, J.: Scalable fabrication of efficient organolead trihalide perovskite solar cells with doctor-bladed active layers. Energy Environ. Sci. 8(5), 1544 (2015).Google Scholar
Barrows, A.T., Pearson, A.J., Kwak, C.K., Dunbar, A.D.F., Buckley, A.R., and Lidzey, D.G.: Efficient planar heterojunction mixed-halide perovskite solar cells deposited via spray-deposition. Energy Environ. Sci. 7(9), 2944 (2014).Google Scholar
Hwang, K., Jung, Y-S., Heo, Y-J., Scholes, F.H., Watkins, S.E., Subbiah, J., Jones, D.J., Kim, D-Y., and Vak, D.: Toward large scale roll-to-roll production of fully printed perovskite solar cells. Adv. Mater. 27(7), 1241 (2015).Google Scholar
Schmidt, T.M., Larsen-Olsen, T.T., Carlé, J.E., Angmo, D., and 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(15), 1500569 (2015).CrossRefGoogle Scholar
Li, G., Tan, Z-K., Di, D., Lai, M.L., Jiang, L., Lim, J.H-W., Friend, R.H., and Greenham, N.C.: Efficient light-emitting diodes based on nanocrystalline perovskite in a dielectric polymer matrix. Nano Lett. 15(4), 2640 (2015).Google Scholar
Kim, Y-H., Cho, H., Heo, J.H., Kim, T-S., Myoung, N., Lee, C-L., Im, S.H., and Lee, T-W.: Multicolored organic/inorganic hybrid perovskite light-emitting diodes. Adv. Mater. 27(7), 1248 (2015).Google Scholar
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., and Lee, T.W.: Overcoming the electroluminescence efficiency limitations of perovskite light-emitting diodes. Science 350(6265), 1222 (2015).Google Scholar
Wang, N., Cheng, L., Ge, R., Zhang, S., Miao, Y., Zou, W., Yi, C., Sun, Y., Cao, Y., Yang, R., Wei, Y., Guo, Q., Ke, Y., Yu, M., Jin, Y., Liu, Y., Ding, Q., Di, D., Yang, L., Xing, G., Tian, H., Jin, C., Gao, F., Friend, R.H., Wang, J., and Huang, W.: Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells. Nat. Photonics 10(11), 699 (2016).Google Scholar
A Web of Science search on the 29th November 2016 for ‘‘Topic = Perovskite solar cell’ and ‘Document type = ‘Review’’’ returned 163 results, including 93 for the 2016 publication year.Google Scholar
Lee, M.M., Teuscher, J., Miyasaka, T., Murakami, T.N., and Snaith, H.J.: Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 338(6107), 643 (2012).Google Scholar
Burschka, J., Pellet, N., Moon, S-J., Humphry-Baker, R., Gao, P., Nazeeruddin, M.K., and Grätzel, M.: Sequential deposition as a route to high-performance perovskite-sensitized solar cells. Nature 499(7458), 316 (2013).Google Scholar
Kojima, A., Teshima, K., Shirai, Y., and Miyasaka, T.: Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. J. Am. Chem. Soc. 131(17), 6050 (2009).Google Scholar
Travis, W., Glover, E.N.K., Bronstein, H., Scanlon, D.O., and Palgrave, R.G.: On the application of the tolerance factor to inorganic and hybrid halide perovskites: A revised system. Chem. Sci. 7(7), 4548 (2016).Google Scholar
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., and Gratzel, M.: Incorporation of rubidium cations into perovskite solar cells improves photovoltaic performance. Science 354(6309), 206 (2016).Google Scholar
Eperon, G.E., Leijtens, T., Bush, K.A., Prasanna, R., Green, T., Wang, J.T.W., McMeekin, D.P., Volonakis, G., Milot, R.L., May, R., Palmstrom, A., Slotcavage, D.J., Belisle, R.A., Patel, J.B., Parrott, E.S., Sutton, R.J., Ma, W., Moghadam, F., Conings, B., Babayigit, A., Boyen, H.G., Bent, S., Giustino, F., Herz, L.M., Johnston, M.B., McGehee, M.D., and Snaith, H.J.: Perovskite–perovskite tandem photovoltaics with optimized band gaps. Science 354(6314), 861 (2016).Google Scholar
Liu, M., Johnston, M.B., and Snaith, H.J.: Efficient planar heterojunction perovskite solar cells by vapour deposition. Nature 501(7467), 395 (2013).Google Scholar
Pistor, P., Borchert, J., Fränzel, W., Csuk, R., and Scheer, R.: Monitoring the phase formation of coevaporated lead halide perovskite thin films by in situ X-ray diffraction. J. Phys. Chem. Lett. 5(19), 3308 (2014).Google Scholar
Stoumpos, C.C., Malliakas, C.D., and Kanatzidis, M.G.: Semiconducting tin and lead iodide perovskites with organic cations: Phase transitions, high mobilities, and near-infrared photoluminescent properties. Inorg. Chem. 52(15), 9019 (2013).Google Scholar
Baikie, T., Fang, Y., Kadro, J.M., Schreyer, M., Wei, F., Mhaisalkar, S.G., Graetzel, M., and White, T.J.: Synthesis and crystal chemistry of the hybrid perovskite (CH3NH3)PbI3 for solid-state sensitised solar cell applications. J. Mater. Chem. A 1(18), 5628 (2013).Google Scholar
Kawamura, Y., Mashiyama, H., and Hasebe, K.: Structural study on cubic–tetragonal transition of CH3NH3PbI3 . J. Phys. Soc. Jpn. 71(7), 1694 (2002).Google Scholar
Wang, Q., Lyu, M., Zhang, M., Yun, J-H., Chen, H., and Wang, L.: Transition from the tetragonal to cubic phase of organohalide perovskite: The role of chlorine in crystal formation of CH3NH3PbI3 on TiO2 substrates. J. Phys. Chem. Lett. 6(21), 4379 (2015).Google Scholar
Noh, J.H., Im, S.H., Heo, J.H., Mandal, T.N., and Seok, S.I.: Chemical management for colorful, efficient, and stable inorganic–organic hybrid nanostructured solar cells. Nano Lett. 13(4), 1764 (2013).Google Scholar
Chen, Q., Zhou, H., Fang, Y., Stieg, A.Z., Song, T-B., Wang, H-H., Xu, X., Liu, Y., Lu, S., You, J., Sun, P., McKay, J., Goorsky, M.S., and Yang, Y.: The optoelectronic role of chlorine in CH3NH3PbI3(Cl)-based perovskite solar cells. Nat. Commun. 6, 7269 (2015).Google Scholar
Stranks, S.D., Eperon, G.E., Grancini, G., Menelaou, C., Alcocer, M.J.P., Leijtens, T., Herz, L.M., Petrozza, A., and Snaith, H.J.: Electron-hole diffusion lengths exceeding 1 micrometer in an organometal trihalide perovskite absorber. Science 342(6156), 341 (2013).Google Scholar
Colella, S., Mosconi, E., Pellegrino, G., Alberti, A., Guerra, V.L.P., Masi, S., Listorti, A., Rizzo, A., Condorelli, G.G., De Angelis, F., and Gigli, G.: Elusive presence of chloride in mixed halide perovskite solar cells. J. Phys. Chem. Lett. 5(20), 3532 (2014).Google Scholar
Grancini, G., Marras, S., Prato, M., Giannini, C., Quarti, C., De Angelis, F., De Bastiani, M., Eperon, G.E., Snaith, H.J., Manna, L., and Petrozza, A.: The impact of the crystallization processes on the structural and optical properties of hybrid perovskite films for photovoltaics. J. Phys. Chem. Lett. 5(21), 3836 (2014).Google Scholar
Yu, H., Wang, F., Xie, F., Li, W., Chen, J., and Zhao, N.: The role of chlorine in the formation process of “CH3NH3PbI3−x Cl x ” perovskite. Adv. Funct. Mater. 24(45), 71027108 (2014).Google Scholar
Dualeh, A., Tétreault, N., Moehl, T., Gao, P., Nazeeruddin, M.K., and Grätzel, M.: Effect of annealing temperature on film morphology of organic–inorganic hybrid pervoskite solid-state solar cells. Adv. Funct. Mater. 24(21), 3250 (2014).Google Scholar
Eperon, G.E., Habisreutinger, S.N., Leijtens, T., Bruijnaers, B.J., van Franeker, J.J., deQuilettes, D.W., Pathak, S., Sutton, R.J., Grancini, G., Ginger, D.S., Janssen, R.A.J., Petrozza, A., and Snaith, H.J.: The importance of moisture in hybrid lead halide perovskite thin film fabrication. ACS Nano 9(9), 9380 (2015).Google Scholar
Leguy, A.M.A., Hu, Y., Campoy-Quiles, M., Alonso, M.I., Weber, O.J., Azarhoosh, P., van Schilfgaarde, M., Weller, M.T., Bein, T., Nelson, J., Docampo, P., and Barnes, P.R.F.: Reversible hydration of CH3NH3PbI3 in films, single crystals, and solar cells. Chem. Mater. 27(9), 3397 (2015).Google Scholar
Unger, E.L., Bowring, A.R., Tassone, C.J., Pool, V.L., Gold-Parker, A., Cheacharoen, R., Stone, K.H., Hoke, E.T., Toney, M.F., and McGehee, M.D.: Chloride in lead chloride-derived organo-metal halides for perovskite-absorber solar cells. Chem. Mater. 26(24), 7158 (2014).Google Scholar
Barrows, A.T., Lilliu, S., Pearson, A.J., Babonneau, D., Dunbar, A.D.F., and Lidzey, D.G.: Monitoring the formation of a CH3NH3PbI3−x Cl x perovskite during thermal annealing using X-ray scattering. Adv. Funct. Mater. 26(27), 4934 (2016).Google Scholar
Moore, D.T., Sai, H., Tan, K.W., Smilgies, D-M., Zhang, W., Snaith, H.J., Wiesner, U., and Estroff, L.A.: Crystallization kinetics of organic–inorganic trihalide perovskites and the role of the lead anion in crystal growth. J. Am. Chem. Soc. 137(6), 2350 (2015).Google Scholar
Tan, K.W., Moore, D.T., Saliba, M., Sai, H., Estroff, L.A., Hanrath, T., Snaith, H.J., and Wiesner, U.: Thermally induced structural evolution and performance of mesoporous block copolymer-directed alumina perovskite solar cells. ACS Nano 8(5), 4730 (2014).Google Scholar
Rossander, L.H., Larsen-Olsen, T.T., Dam, H.F., Schmidt, T.M., Corazza, M., Norrman, K., Rajkovic, I., Andreasen, J.W., and Krebs, F.C.: In situ X-ray scattering of perovskite solar cell active layers roll-to-roll coated on flexible substrates. CrystEngComm 18(27), 5083 (2016).Google Scholar
Nenon, D.P., Christians, J.A., Wheeler, L.M., Blackburn, J.L., Sanehira, E.M., Dou, B., Olsen, M.L., Zhu, K., Berry, J.J., and Luther, J.M.: Structural and chemical evolution of methylammonium lead halide perovskites during thermal processing from solution. Energy Environ. Sci. 9(6), 2072 (2016).Google Scholar
Chang, C-Y., Huang, Y-C., Tsao, C-S., and Su, W-F.: Formation mechanism and control of perovskite films from solution to crystalline phase studied by in situ synchrotron scattering. ACS Appl. Mater. Interfaces 8(40), 26712 (2016).Google Scholar
Lilliu, S., Griffin, J., Barrows, A.T., Alsari, M., Curzadd, B., Dane, T.G., Bikondoa, O., Macdonald, J.E., and Lidzey, D.G.: Grain rotation and lattice deformation during perovskite spray coating and annealing probed in situ by GI-WAXS. CrystEngComm 18(29), 5448 (2016).Google Scholar
Williams, S.T., Zuo, F., Chueh, C-C., Liao, C-Y., Liang, P-W., and Jen, A.K.Y.: Role of chloride in the morphological evolution of organo-lead halide perovskite thin films. ACS Nano 8(10), 10640 (2014).Google Scholar
Eperon, G.E., Burlakov, V.M., Docampo, P., Goriely, A., and Snaith, H.J.: Morphological control for high performance, solution-processed planar heterojunction perovskite solar cells. Adv. Funct. Mater. 24(1), 151 (2014).Google Scholar
Kang, R., Kim, J-E., Yeo, J-S., Lee, S., Jeon, Y-J., and Kim, D-Y.: Optimized organometal halide perovskite planar hybrid solar cells via control of solvent evaporation rate. J. Phys. Chem. C 118(46), 26513 (2014).Google Scholar
Xu, M-F., Zhang, H., Zhang, S., Zhu, H.L., Su, H-M., Liu, J., Wong, K.S., Liao, L-S., and Choy, W.C.H.: A low temperature gradual annealing scheme for achieving high performance perovskite solar cells with no hysteresis. J. Mater. Chem. A 3(27), 14424 (2015).Google Scholar
Cao, D.H., Stoumpos, C.C., Malliakas, C.D., Katz, M.J., Farha, O.K., Hupp, J.T., and Kanatzidis, M.G.: Remnant PbI2, an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells? APL Mater. 2(9), 091101 (2014).Google Scholar
Jacobsson, T.J., Correa-Baena, J-P., Halvani Anaraki, E., Philippe, B., Stranks, S.D., Bouduban, M.E.F., Tress, W., Schenk, K., Teuscher, J., Moser, J-E., Rensmo, H., and Hagfeldt, A.: Unreacted PbI2 as a double-edged sword for enhancing the performance of perovskite solar cells. J. Am. Chem. Soc. 138(32), 10331 (2016).Google Scholar
Liu, F., Dong, Q., Wong, M.K., Djurišić, A.B., Ng, A., Ren, Z., Shen, Q., Surya, C., Chan, W.K., Wang, J., Ng, A.M.C., Liao, C., Li, H., Shih, K., Wei, C., Su, H., and Dai, J.: Is excess PbI2 beneficial for perovskite solar cell performance? Adv. Energy Mater. 6(7), 1502206 (2016).Google Scholar
Chen, Q., Zhou, H., Hong, Z., Luo, S., Duan, H-S., Wang, H-H., Liu, Y., Li, G., and Yang, Y.: Planar heterojunction perovskite solar cells via vapor-assisted solution process. J. Am. Chem. Soc. 136(2), 622 (2014).Google Scholar
Zhou, Z., Wang, Z., Zhou, Y., Pang, S., Wang, D., Xu, H., Liu, Z., Padture, N.P., and Cui, G.: Methylamine-gas-induced defect-healing behavior of CH3NH3PbI3 thin films for perovskite solar cells. Angew. Chem., Int. Ed. 54(33), 9705 (2015).Google Scholar
Xiao, Z., Dong, Q., Bi, C., Shao, Y., Yuan, Y., and Huang, J.: Solvent annealing of perovskite-induced crystal growth for photovoltaic-device efficiency enhancement. Adv. Mater. 26(37), 6503 (2014).Google Scholar
Yu, H., Liu, X., Xia, Y., Dong, Q., Zhang, K., Wang, Z., Zhou, Y., Song, B., and Li, Y.: Room-temperature mixed-solvent-vapor annealing for high performance perovskite solar cells. J. Mater. Chem. A 4(1), 321 (2016).Google Scholar
You, J., Yang, Y., Hong, Z., Song, T-B., Meng, L., Liu, Y., Jiang, C., Zhou, H., Chang, W-H., Li, G., and Yang, Y.: Moisture assisted perovskite film growth for high performance solar cells. Appl. Phys. Lett. 105(18), 183902 (2014).Google Scholar
Urai, J.L.: Water assisted dynamic recrystallization and weakening in polycrystalline bischofite. Tectonophysics 96(1–2), 125 (1983).Google Scholar
Petrus, M.L., Hu, Y., Moia, D., Calado, P., Leguy, A.M.A., Barnes, P.R.F., and Docampo, P.: The influence of water vapor on the stability and processing of hybrid perovskite solar cells made from non-stoichiometric precursor mixtures. Chemsuschem 9(18), 2699 (2016).Google Scholar
Zhang, W., Saliba, M., Moore, D.T., Pathak, S.K., Hörantner, M.T., Stergiopoulos, T., Stranks, S.D., Eperon, G.E., Alexander-Webber, J.A., Abate, A., Sadhanala, A., Yao, S., Chen, Y., Friend, R.H., Estroff, L.A., Wiesner, U., and Snaith, H.J.: Ultrasmooth organic–inorganic perovskite thin-film formation and crystallization for efficient planar heterojunction solar cells. Nat. Commun. 6, 6142 (2015).Google Scholar
Jeon, N.J., Noh, J.H., Kim, Y.C., Yang, W.S., Ryu, S., and Seok, S.I.: Solvent engineering for high-performance inorganic–organic hybrid perovskite solar cells. Nat. Mater. 13(9), 897 (2014).Google Scholar
Noel, N.K., Habisreutinger, S.N., Wenger, B., Klug, M.T., Hörantner, M.T., Johnston, M.B., Nicholas, R.J., Moore, D.T., and Snaith, H.J.: A low viscosity, low boiling point, clean solvent system for the rapid crystallisation of highly specular perovskite films. Energy Environ. Sci. 10, 145152 (2017).Google Scholar
Liang, P-W., Liao, C-Y., Chueh, C-C., Zuo, F., Williams, S.T., Xin, X-K., Lin, J., and Jen, A.K.Y.: Additive enhanced crystallization of solution-processed perovskite for highly efficient planar-heterojunction solar cells. Adv. Mater. 26(22), 3748 (2014).Google Scholar
Chueh, C-C., Liao, C-Y., Zuo, F., Williams, S.T., Liang, P-W., and Jen, A.K.Y.: The roles of alkyl halide additives in enhancing perovskite solar cell performance. J. Mater. Chem. A 3(17), 9058 (2015).Google Scholar
Manser, J.S., Reid, B., and Kamat, P.V.: Evolution of organic–inorganic lead halide perovskite from solid-state iodoplumbate complexes. J. Phys. Chem. C 119(30), 17065 (2015).Google Scholar
Yoon, S.J., Stamplecoskie, K.G., and Kamat, P.V.: How lead halide complex chemistry dictates the composition of mixed halide perovskites. J. Phys. Chem. Lett. 7(7), 1368 (2016).Google Scholar
Zhang, W., Pathak, S., Sakai, N., Stergiopoulos, T., Nayak, P.K., Noel, N.K., Haghighirad, A.A., Burlakov, V.M., deQuilettes, D.W., Sadhanala, A., Li, W., Wang, L., Ginger, D.S., Friend, R.H., and Snaith, H.J.: Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells. Nat. Commun. 6, 10030 (2015).Google Scholar
Jung, J.W., Williams, S.T., and Jen, A.K.Y.: Low-temperature processed high-performance flexible perovskite solar cells via rationally optimized solvent washing treatments. RSC Adv. 4(108), 62971 (2014).Google Scholar
Ahn, N., Son, D-Y., Jang, I-H., Kang, S.M., Choi, M., and 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(27), 8696 (2015).Google Scholar
Miyadera, T., Shibata, Y., Koganezawa, T., Murakami, T.N., Sugita, T., Tanigaki, N., and Chikamatsu, M.: Crystallization dynamics of organolead halide perovskite by real-time X-ray diffraction. Nano Lett. 15(8), 5630 (2015).Google Scholar
Yang, B., Keum, J., Ovchinnikova, O.S., Belianinov, A., Chen, S., Du, M-H., Ivanov, I.N., Rouleau, C.M., Geohegan, D.B., and Xiao, K.: Deciphering halogen competition in organometallic halide perovskite growth. J. Am. Chem. Soc. 138(15), 5028 (2016).Google Scholar
Eperon, G.E., Stranks, S.D., Menelaou, C., Johnston, M.B., Herz, L.M., and Snaith, H.J.: Formamidinium lead trihalide: A broadly tunable perovskite for efficient planar heterojunction solar cells. Energy Environ. Sci. 7(3), 982 (2014).Google Scholar
Koh, T.M., Fu, K., Fang, Y., Chen, S., Sum, T.C., Mathews, N., Mhaisalkar, S.G., Boix, P.P., and Baikie, T.: Formamidinium-containing metal-halide: An alternative material for near-IR absorption perovskite solar cells. J. Phys. Chem. C 118(30), 16458 (2014).Google Scholar
Aguiar, J.A., Wozny, S., Holesinger, T.G., Aoki, T., Patel, M.K., Yang, M., Berry, J.J., Al-Jassim, M., Zhou, W., and Zhu, K.: In situ investigation of the formation and metastability of formamidinium lead tri-iodide perovskite solar cells. Energy Environ. Sci. 9(7), 2372 (2016).Google Scholar
Leyden, M.R., Lee, M.V., Raga, S.R., and Qi, Y.: Large formamidinium lead trihalide perovskite solar cells using chemical vapor deposition with high reproducibility and tunable chlorine concentrations. J. Mater. Chem. A 3(31), 16097 (2015).Google Scholar
Yang, J., Siempelkamp, B.D., Liu, D., and Kelly, T.L.: Investigation of CH3NH3PbI3 degradation rates and mechanisms in controlled humidity environments using in situ techniques. ACS Nano 9(2), 1955 (2015).Google Scholar
Aristidou, N., Sanchez-Molina, I., Chotchuangchutchaval, T., Brown, M., Martinez, L., Rath, T., and Haque, S.A.: The role of oxygen in the degradation of methylammonium lead trihalide perovskite photoactive layers. Angew. Chem., Int. Ed. 54(28), 8208 (2015).Google Scholar
Bryant, D., Aristidou, N., Pont, S., Sanchez-Molina, I., Chotchunangatchaval, T., Wheeler, S., Durrant, J.R., and Haque, S.A.: Light and oxygen induced degradation limits the operational stability of methylammonium lead triiodide perovskite solar cells. Energy Environ. Sci. 9(5), 1655 (2016).Google Scholar
Pearson, A.J., Eperon, G.E., Hopkinson, P.E., Habisreutinger, S.N., Wang, J.T-W., Snaith, H.J., and Greenham, N.C.: Oxygen degradation in mesoporous Al2O3/CH3NH3PbI3−x Cl x perovskite solar cells: Kinetics and mechanisms. Adv. Energy Mater. 6(13), 1600014 (2016).Google Scholar
Huang, Y., Kramer, E.J., Heeger, A.J., and Bazan, G.C.: Bulk heterojunction solar cells: Morphology and performance relationships. Chem. Rev. 114(14), 7006 (2014).Google Scholar
Lu, L., Zheng, T., Wu, Q., Schneider, A.M., Zhao, D., and Yu, L.: Recent advances in bulk heterojunction polymer solar cells. Chem. Rev. 115(23), 12666 (2015).Google Scholar
Brady, M.A., Su, G.M., and Chabinyc, M.L.: Recent progress in the morphology of bulk heterojunction photovoltaics. Soft Matter 7(23), 11065 (2011).Google Scholar
Bardeen, C.J.: The structure and dynamics of molecular excitons. Annu. Rev. Phys. Chem. 65(1), 127 (2014).Google Scholar
Bakulin, A.A., Rao, A., Pavelyev, V.G., van Loosdrecht, P.H.M., Pshenichnikov, M.S., Niedzialek, D., Cornil, J., Beljonne, D., and Friend, R.H.: The role of driving energy and delocalized states for charge separation in organic semiconductors. Science 335(6074), 1340 (2012).Google Scholar
Gelinas, S., Rao, A., Kumar, A., Smith, S.L., Chin, A.W., Clark, J., van der Poll, T.S., Bazan, G.C., and Friend, R.H.: Ultrafast long-range charge separation in organic semiconductor photovoltaic diodes. Science 343(6170), 512 (2013).Google Scholar
Jamieson, F.C., Domingo, E.B., McCarthy-Ward, T., Heeney, M., Stingelin, N., and Durrant, J.R.: Fullerene crystallisation as a key driver of charge separation in polymer/fullerene bulk heterojunction solar cells. Chem. Sci. 3(2), 485 (2012).Google Scholar
Friend, R.H., Phillips, M., Rao, A., Wilson, M.W.B., Li, Z., and McNeill, C.R.: Excitons and charges at organic semiconductor heterojunctions. Faraday Discuss. 155, 339 (2012).Google Scholar
Clarke, T.M. and Durrant, J.R.: Charge photogeneration in organic solar cells. Chem. Rev. 110(11), 6736 (2010).Google Scholar
Halls, J.J.M., Pichler, K., Friend, R.H., Moratti, S.C., and Holmes, A.B.: Exciton diffusion and dissociation in a poly(p-phenylenevinylene)/C60 heterojunction photovoltaic cell. Appl. Phys. Lett. 68(22), 3120 (1996).Google Scholar
Shaw, P.E., Ruseckas, A., and Samuel, I.D.W.: Exciton diffusion measurements in poly(3-hexylthiophene). Adv. Mater. 20(18), 3516 (2008).Google Scholar
Dang, M.T., Hirsch, L., and Wantz, G.: P3HT:PCBM, best seller in polymer photovoltaic research. Adv. Mater. 23(31), 3597 (2011).Google Scholar
Wang, T., Dunbar, A.D.F., Staniec, P.A., Pearson, A.J., Hopkinson, P.E., MacDonald, J.E., Lilliu, S., Pizzey, C., Terrill, N.J., Donald, A.M., Ryan, A.J., Jones, R.A.L., and Lidzey, D.G.: The development of nanoscale morphology in polymer:fullerene photovoltaic blends during solvent casting. Soft Matter 6(17), 4128 (2010).Google Scholar
Schmidt-Hansberg, B., Sanyal, M., Klein, M.F.G., Pfaff, M., Schnabel, N., Jaiser, S., Vorobiev, A., Müller, E., Colsmann, A., Scharfer, P., Gerthsen, D., Lemmer, U., Barrena, E., and Schabel, W.: Moving through the phase diagram: Morphology formation in solution cast polymer–fullerene blend films for organic solar cells. ACS Nano 5(11), 8579 (2011).Google Scholar
Pearson, A.J., Wang, T., Dunbar, A.D.F., Yi, H., Watters, D.C., Coles, D.M., Staniec, P.A., Iraqi, A., Jones, R.A.L., and Lidzey, D.G.: Morphology development in amorphous polymer:fullerene photovoltaic blend films during solution casting. Adv. Funct. Mater. 24(5), 659 (2014).Google Scholar
Liu, F., Gu, Y., Wang, C., Zhao, W., Chen, D., Briseno, A.L., and Russell, T.P.: Efficient polymer solar cells based on a low band gap semi-crystalline DPP polymer–PCBM blends. Adv. Mater. 24(29), 3947 (2012).Google Scholar
Liu, F., Ferdous, S., Schaible, E., Hexemer, A., Church, M., Ding, X., Wang, C., and Russell, T.P.: Fast printing and in situ morphology observation of organic photovoltaics using slot-die coating. Adv. Mater. 27(5), 886 (2015).Google Scholar
van Franeker, J.J., Turbiez, M., Li, W., Wienk, M.M., and Janssen, R.A.J.: A real-time study of the benefits of co-solvents in polymer solar cell processing. Nat. Commun. 6, 6229 (2015).Google Scholar
Liao, H-C., Ho, C-C., Chang, C-Y., Jao, M-H., Darling, S.B., and Su, W-F.: Additives for morphology control in high-efficiency organic solar cells. Mater. Today 16(9), 326 (2013).Google Scholar
Lee, J.K., Ma, W.L., Brabec, C.J., Yuen, J., Moon, J.S., Kim, J.Y., Lee, K., Bazan, G.C., and Heeger, A.J.: Processing additives for improved efficiency from bulk heterojunction solar cells. J. Am. Chem. Soc. 130(11), 3619 (2008).Google Scholar
Liu, F., Zhao, W., Tumbleston, J.R., Wang, C., Gu, Y., Wang, D., Briseno, A.L., Ade, H., and Russell, T.P.: Understanding the morphology of PTB7:PCBM blends in organic photovoltaics. Adv. Energy Mater. 4(5), 1301377 (2014).Google Scholar
Tremolet de Villers, B.J., O’Hara, K.A., Ostrowski, D.P., Biddle, P.H., Shaheen, S.E., Chabinyc, M.L., Olson, D.C., and Kopidakis, N.: Removal of residual diiodooctane improves photostability of high-performance organic solar cell polymers. Chem. Mater. 28(3), 876 (2016).Google Scholar
Richter, L.J., DeLongchamp, D.M., Bokel, F.A., Engmann, S., Chou, K.W., Amassian, A., Schaible, E., and Hexemer, A.: In situ morphology studies of the mechanism for solution additive effects on the formation of bulk heterojunction films. Adv. Energy Mater. 5(3), 1400975 (2015).Google Scholar
Pearson, A.J., Wang, T., Jones, R.A.L., Lidzey, D.G., Staniec, P.A., Hopkinson, P.E., and Donald, A.M.: Rationalizing phase transitions with thermal annealing temperatures for P3HT:PCBM organic photovoltaic devices. Macromolecules 45(3), 1499 (2012).Google Scholar
Treat, N.D., Brady, M.A., Smith, G., Toney, M.F., Kramer, E.J., Hawker, C.J., and Chabinyc, M.L.: Interdiffusion of PCBM and P3HT reveals miscibility in a photovoltaically active blend. Adv. Energy Mater. 1(1), 82 (2011).Google Scholar
Chou, K.W., Yan, B., Li, R., Li, E.Q., Zhao, K., Anjum, D.H., Alvarez, S., Gassaway, R., Biocca, A., Thoroddsen, S.T., Hexemer, A., and Amassian, A.: Spin-cast bulk heterojunction solar cells: A dynamical investigation. Adv. Mater. 25(13), 1923 (2013).Google Scholar
Perez, L.A., Chou, K.W., Love, J.A., van der Poll, T.S., Smilgies, D-M., Nguyen, T-Q., Kramer, E.J., Amassian, A., and Bazan, G.C.: Solvent additive effects on small molecule crystallization in bulk heterojunction solar cells probed during spin casting. Adv. Mater. 25(44), 6380 (2013).Google Scholar
Engmann, S., Bokel, F.A., Herzing, A.A., Ro, H.W., Girotto, C., Caputo, B., Hoven, C.V., Schaible, E., Hexemer, A., DeLongchamp, D.M., and Richter, L.J.: Real-time X-ray scattering studies of film evolution in high performing small-molecule–fullerene organic solar cells. J. Mater. Chem. A 3(16), 8764 (2015).Google Scholar
Liu, Y., Zhao, J., Li, Z., Mu, C., Ma, W., Hu, H., Jiang, K., Lin, H., Ade, H., and Yan, H.: Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells. Nat. Commun. 5, 5293 (2014).Google Scholar
Ro, H.W., Downing, J.M., Engmann, S., Herzing, A.A., DeLongchamp, D.M., Richter, L.J., Mukherjee, S., Ade, H., Abdelsamie, M., Jagadamma, L.K., Amassian, A., Liu, Y., and Yan, H.: Morphology changes upon scaling a high-efficiency, solution-processed solar cell. Energy Environ. Sci. 9(9), 2835 (2016).Google Scholar
Zhao, K., Hu, H., Spada, E., Jagadamma, L.K., Yan, B., Abdelsamie, M., Yang, Y., Yu, L., Munir, R., Li, R., Ndjawa, G.O.N., and Amassian, A.: Highly efficient polymer solar cells with printed photoactive layer: Rational process transfer from spin-coating. J. Mater. Chem. A 4(41), 16036 (2016).Google Scholar
Collins, B.A., Gann, E., Guignard, L., He, X., McNeill, C.R., and Ade, H.: Molecular miscibility of polymer–fullerene blends. J. Phys. Chem. Lett. 1(21), 3160 (2010).Google Scholar
Wang, T., Pearson, A.J., Lidzey, D.G., and Jones, R.A.L.: Evolution of structure, optoelectronic properties, and device performance of polythiophene: Fullerene solar cells during thermal annealing. Adv. Funct. Mater. 21(8), 1383 (2011).Google Scholar
Sharenko, A., Kuik, M., Toney, M.F., and Nguyen, T-Q.: Crystallization-induced phase separation in solution-processed small molecule bulk heterojunction organic solar cells. Adv. Funct. Mater. 24(23), 3543 (2014).Google Scholar
Engmann, S., Ro, H.W., Herzing, A., Snyder, C.R., Richter, L.J., Geraghty, P.B., and Jones, D.J.: Film morphology evolution during solvent vapor annealing of highly efficient small molecule donor/acceptor blends. J. Mater. Chem. A 4(40), 15511 (2016).Google Scholar
Verploegen, E., Miller, C.E., Schmidt, K., Bao, Z., and Toney, M.F.: Manipulating the morphology of P3HT–PCBM bulk heterojunction blends with solvent vapor annealing. Chem. Mater. 24(20), 3923 (2012).Google Scholar
Schaffer, C.J., Palumbiny, C.M., Niedermeier, M.A., Jendrzejewski, C., Santoro, G., Roth, S.V., and Müller-Buschbaum, P.: A direct evidence of morphological degradation on a nanometer scale in polymer solar cells. Adv. Mater. 25(46), 6760 (2013).Google Scholar
Wang, W., Schaffer, C.J., Song, L., Körstgens, V., Pröller, S., Indari, E.D., Wang, T., Abdelsamie, A., Bernstorff, S., and Müller-Buschbaum, P.: In operando morphology investigation of inverted bulk heterojunction organic solar cells by GISAXS. J. Mater. Chem. A 3(16), 8324 (2015).Google Scholar
Hopkinson, P.E., Staniec, P.A., Pearson, A.J., Dunbar, A.D.F., Wang, T., Ryan, A.J., Jones, R.A.L., Lidzey, D.G., and Donald, A.M.: A phase diagram of the P3HT:PCBM organic photovoltaic system: Implications for device processing and performance. Macromolecules 44(8), 2908 (2011).Google Scholar
Li, Z., Wong, H.C., Huang, Z., Zhong, H., Tan, C.H., Tsoi, W.C., Kim, J.S., Durrant, J.R., and Cabral, J.T.: Performance enhancement of fullerene-based solar cells by light processing. Nat. Commun. 4, 2227 (2013).Google Scholar
Leblebici, S.Y., Leppert, L., Li, Y., Reyes-Lillo, S.E., Wickenburg, S., Wong, E., Lee, J., Melli, M., Ziegler, D., Angell, D.K., Ogletree, D.F., Ashby, P.D., Toma, F.M., Neaton, J.B., Sharp, I.D., and Weber-Bargioni, A.: Facet-dependent photovoltaic efficiency variations in single grains of hybrid halide perovskite. Nat. Energy 1(8), 16093 (2016).Google Scholar
Lilliu, S., Dane, T.G., Alsari, M., Griffin, J., Barrows, A.T., Dahlem, M.S., Friend, R.H., Lidzey, D.G., and Macdonald, J.E.: Mapping morphological and structural properties of lead halide perovskites by scanning nanofocus XRD. Adv. Funct. Mater. 26(45), 8221 (2016).Google Scholar
Li, X., Bi, D., Yi, C., Decoppet, J.D., Luo, J., Zakeeruddin, S.M., Hagfeldt, A., and Gratzel, M.: A vacuum flash-assisted solution process for high-efficiency large-area perovskite solar cells. Science 353(6294), 58 (2016).Google Scholar
Zhao, W., Qian, D., Zhang, S., Li, S., Inganäs, O., Gao, F., and Hou, J.: Fullerene-free polymer solar cells with over 11% efficiency and excellent thermal stability. Adv. Mater. 28(23), 4734 (2016).Google Scholar