Resonant soft x-ray scattering unravels the hierarchical morphology of nanostructured bulk heterojunction photovoltaic thin films

Álvaro Rodríguez-Rodríguez, Mari-Cruz García-Gutiérrez, Tiberio A. Ezquerra, Michael A. Brady, Cheng Wang, and Esther Rebollar

Phys. Rev. Materials 2, 066003 – Published 20 June 2018

Abstract

Resonant soft x-ray scattering at the carbon $K$ edge is shown to be an unambiguous approach to evaluate the phase segregation between donor and acceptor phases across the grooves of a laser-induced periodic surface nanostructure on a paradigmatic poly(3-hexylthiophene)/fullerene bulk heterojunction. By taking advantage of the use of polarized soft x rays, the results provide direct evidence that the formation of the nanostructure on the surface of the heterojunction induces not only additional phase separation of the two components but also a preferential directional arrangement of the different phases.

Received 20 December 2017
Revised 9 May 2018

DOI:https://doi.org/10.1103/PhysRevMaterials.2.066003

Physics Subject Headings (PhySH)

Crystal orientation Organic electronics Pattern formation Phase separation Self-assembly

Thin films

X-ray scattering

Polymers & Soft Matter

Authors & Affiliations

Álvaro Rodríguez-Rodríguez¹, Mari-Cruz García-Gutiérrez^1,*, Tiberio A. Ezquerra¹, Michael A. Brady², Cheng Wang², and Esther Rebollar³

¹Instituto de Estructura de la Materia (IEM-CSIC), Serrano 121, 28006 Madrid, Spain
²Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
³Instituto de Química Física Rocasolano (IQFR-CSIC), Serrano 119, 28006 Madrid, Spain