Mapping fullerene crystallization in a photovoltaic blend: an electron tomography study
Artikel i vetenskaplig tidskrift, 2015

The formation of fullerene crystals represents a major degradation pathway of polymer/fullerene bulk-heterojunction thin films that inexorably deteriorates their photovoltaic performance. Currently no tools exist that reveal the origin of fullerene crystal formation vertically through the film. Here, we show that electron tomography can be used to study nucleation and growth of fullerene crystals. A model bulk-heterojunction blend based on a thiophene-quinoxaline copolymer and a fullerene derivative is examined after controlled annealing above the glass transition temperature. We image a number of fullerene nanocrystals, ranging in size from 70 to 400 nanometers, and observe that their center is located close to the free-surface of spin-coated films. The results show that the nucleation of fullerene crystals predominately occurs in the upper part of the films. Moreover, electron tomography reveals that the nucleation is preceded by more pronounced phase separation of the blend components.

Författare

Olof Bäcke

Chalmers, Teknisk fysik, Eva Olsson Group

Camilla Lindqvist

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Amaia Diaz de Zerio Mendaza

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Stefan Gustafsson

SuMo Biomaterials

Chalmers, Teknisk fysik, Eva Olsson Group

Ergang Wang

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Mats Andersson

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Christian Müller

Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Eva Olsson

Chalmers, Teknisk fysik, Eva Olsson Group

Nanoscale

2040-3364 (ISSN)

Vol. 7 8451-8456

Ämneskategorier

Polymerkemi

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Materialvetenskap

DOI

10.1039/c5nr00443h