In situ X-ray scattering studies of the influence of an additive on the formation of a low-bandgap bulk- heterojunction

Published

February 21, 2017

Author(s)

Felicia A. Bokel, Lee J. Richter, Sebastian Engmann, Andrew Herzing, Brian A. Collins, Hyun W. Ro, Dean DeLongchamp

Abstract

The evolution of the morphology of a high-efficiency, blade-coated, organic-photovoltaic (OPV) active layer containing the low band-gap polymer poly[(4,8-bis[5-(2-ethylhexyl)thiophene-2-yl]benzo[1,2-b:4,5-b']dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene))-2,6-diyl] (PBDTTT-C-T) is examined by in situ X-ray scattering. In situ studies enable real-time characterization of the effect of the processing additive 1,8 diiodoocatane (DIO) on the active layer morphology. In the presence of DIO, domains become smaller and increase in purity, whereas GIXD reveals increased order of the lamella but little change in total crystallinity. The solidification behavior of this active layer differs dramatically from those that strongly crystallize such as poly(3-hexylthiophene) and small molecule - containing systems, exposing significant diversity in the solidification routes relevant to high-efficiency polymer-fullerene OPV processing.

Citation

Advanced Energy Materials

Pub Type

Journals

Keywords

Polymer, Organic, photovoltaic, X-ray, scattering, diffraction, kinetics, thin film, processing

Citation

Bokel, F. , Richter, L. , Engmann, S. , Herzing, A. , Collins, B. , Ro, H. and DeLongchamp, D. (2017), In situ X-ray scattering studies of the influence of an additive on the formation of a low-bandgap bulk- heterojunction, Advanced Energy Materials (Accessed October 11, 2024)