TY - JOUR
T1 - In Situ GIWAXS Analysis of Solvent and Additive Effects on PTB7 Thin Film Microstructure Evolution during Spin Coating
AU - Manley, Eric F.
AU - Strzalka, Joseph
AU - Fauvell, Thomas J.
AU - Jackson, Nicholas E.
AU - Leonardi, Matthew J.
AU - Eastham, Nicholas D.
AU - Marks, Tobin J.
AU - Chen, Lin X.
N1 - E.F.M., T.J.F., M.J.L., N.D.E., L.X.C., and T.J.M. acknowledge financial support from Argonne-Northwestern Solar Energy Research (ANSER) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001059, by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under Award Number DE-FG02-08ER46536. N.E.J. thanks the Northwestern Presidential Fellowship for support. E.F.M. was also supported by Qatar NPRP grant 7-286-1-046. M.J.L. also acknowledges previous support from the NDSEG for a predoctoral fellowship. Solution scattering was performed at the DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT) located at Sector 5 of the Advanced Photon Source (APS). DND-CAT was supported by Northwestern University, E.I. DuPont de Nemours & Co., and The Dow Chemical Company. Solution scattering data was collected using an instrument funded by the National Science Foundation under Award Number 0960140. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357.
PY - 2017/11/20
Y1 - 2017/11/20
N2 - The influence of solvent and processing additives on the pathways and rates of crystalline morphology formation for spin-coated semiconducting PTB7 (poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]-thieno[3,4-b]thiophenediyl]]) thin films is investigated by in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and optical reflectance, to better understand polymer solar cell (PSC) optimization approaches. In situ characterization of PTB7 film formation from chloroform (CF), chlorobenzene (CB), and 1,2-dichlorobenzene (DCB) solutions, as well as CB solutions with 1% and 3% v/v of the processing additives 1-chloronapthalene (CN), diphenylether (DPE), and 1,8-diiodooctane (DIO), reveals multiple crystallization pathways with: (i) single-solvent systems exhibiting rapid (<3 s) crystallization after a solvent boiling point-dependent film thinning transition, (ii) solvent + additive systems exhibiting different crystallization pathways and crystallite formation times from minutes (CN, DPE) to 1.5 h (DIO). Identifying crystalline intermediates has implications for bulk-heterojunction PSC morphology optimization via optimized spin-casting processes.
AB - The influence of solvent and processing additives on the pathways and rates of crystalline morphology formation for spin-coated semiconducting PTB7 (poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]-thieno[3,4-b]thiophenediyl]]) thin films is investigated by in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and optical reflectance, to better understand polymer solar cell (PSC) optimization approaches. In situ characterization of PTB7 film formation from chloroform (CF), chlorobenzene (CB), and 1,2-dichlorobenzene (DCB) solutions, as well as CB solutions with 1% and 3% v/v of the processing additives 1-chloronapthalene (CN), diphenylether (DPE), and 1,8-diiodooctane (DIO), reveals multiple crystallization pathways with: (i) single-solvent systems exhibiting rapid (<3 s) crystallization after a solvent boiling point-dependent film thinning transition, (ii) solvent + additive systems exhibiting different crystallization pathways and crystallite formation times from minutes (CN, DPE) to 1.5 h (DIO). Identifying crystalline intermediates has implications for bulk-heterojunction PSC morphology optimization via optimized spin-casting processes.
KW - additives
KW - in situ GIWAXS
KW - organic photovoltaics
KW - PTB7
KW - spin coating
UR - https://www.scopus.com/pages/publications/85030638630
UR - https://www.scopus.com/pages/publications/85030638630#tab=citedBy
U2 - 10.1002/adma.201703933
DO - 10.1002/adma.201703933
M3 - Article
C2 - 28990271
AN - SCOPUS:85030638630
SN - 0935-9648
VL - 29
JO - Advanced Materials
JF - Advanced Materials
IS - 43
M1 - 1703933
ER -