Page 239 - A Comprehensive Guide to Solar Energy Systems

242 A COMPREHENSIVE GUIdE TO SOLAR ENERGy SySTEMS

Xiao et al. [79] demonstrated fast-deposition crystallization (FdC) procedure to yield
highly uniform perovskite film using a spin coating of a dMF solution of MAPbI 3 followed
immediately by the addition of chlorobenzene to induce crystallization. In this method, a
rapid reduction of solubility of MAPbI 3 occurs with a fast nucleation and growth as a result
of the addition of the second solution. The film fabricated by FdC produces a very large
grain and full surface coverage in contrast to incomplete coverage obtained by conven-
tional spin coating. A new concept of solvent–solvent extraction was proposed to fabricate
high quality perovskite films at room temperature [80]. In this method, perovskite film is
spun coated in a high boiling point solvent like N-methyl-2-pyrrolidone (NMP) and the
wet film is immediately transferred into a low boiling point solvent like diethyl ether for
the crystallization of smooth perovskite films. Other antisolvents used in fabricating high
quality film are benzene and xylene [79]. Fig. 11.6 demonstrates morphological and struc-
tural characterization of MAPbI 3 films prepared by several deposition techniques.

FIGURE 11.6 Morphology control of hybrid organic–inorganic metal halide perovskite films: SEM images of CH 3 NH 3 PbI 3
obtained from (A) one-step spin coating, (B) two-steps spin coating, (C) one-step spin coating with toluene treatment,
(D) thermal annealing of toluene treated film, (E) solvent–solvent extraction method, (F) vapor assisted deposition
method, (G) vapor deposition method, (H) fast deposition crystallization method. (D) Reprinted with permission
from Lin Q, Armin A, Burn PL, Meredith P. Organohalide perovskites for solar energy conversion. Account Chem Res
2016:49:545–553, copyright (2016), American Chemical Society, (E) reprinted with permission from Zhou Y, Yang M,
Wu W, Vasiliev AL, Zhu K, Padture NP. Room-temperature crystallization of hybrid-perovskite thin films via solvent–
solvent extraction for high-performance solar cells. J Mater Chem A 2015;3:8178–84, copyright (2015) Royal Society
of Chemistry, (F) Reprinted with permission of Chen Q, Zhou H, Hong Z, Luo S, Duan H-S, Wang H-H, Liu Y, Li G, Yang
Y. Planar heterojunction perovskite solar cells via vapor-assisted solution process. J Am Chem Soc 2013; 136:622–5,
copyright (2013) American Chemical Society, (G) reprinted with permission from Liu M, Johnston MB, Snaith HJ. Efficient
planar heterojunction perovskite solar cells by vapour deposition. Nature 2013;501:395–8, copyright (2013) Nature
Publishing Group, and (H) Reprinted with permission from Xiao M, Huang F, Huang W, Dkhissi Y, Zhu Y, Etheridge J,
Gray-Weale A, Bach U, Cheng Y-B, Spiccia LA. Fast deposition-crystallization procedure for highly efficient lead iodide
perovskite thin-film solar cells. Angew Chem Int Ed 2014;53:9898–903, copyright 2014, WILEY-VCH.