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Measuring domain sizes and compositional heterogeneities in P3HT-PCBM bulk heterojunction thin films with 1H spin diffusion NMR spectroscopy
Published
Author(s)
Ryan C. Nieuwendaal, Hyun Wook Ro, David Germack, Regis J. Kline, Calvin Chan, Amit K. Agrawal, David J. Gundlach, David L. VanderHart, Dean M. DeLongchamp
Abstract
In this manuscript we show that 1H spin diffusion NMR is a valuable method for estimating the domain sizes in thin films of a polymer-fullerene blend for bulk heterojunction (BHJ) photovoltaics. Variations in common BHJ film processing parameters have dramatic effects on the domain sizes in the blend films, which in turn affect power conversion efficiency. Spin-coating rotational speed, thermal annealing schedule, and solvent annealing all strongly affect BHJ morphology. The 1H spin diffusion NMR data clearly show that films spun at fast speeds are primarily composed of small (
Nieuwendaal, R.
, , H.
, Germack, D.
, Kline, R.
, Chan, C.
, Agrawal, A.
, Gundlach, D.
, VanderHart, D.
and DeLongchamp, D.
(2012),
Measuring domain sizes and compositional heterogeneities in P3HT-PCBM bulk heterojunction thin films with 1H spin diffusion NMR spectroscopy, Advanced Functional Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908099
(Accessed October 10, 2025)