A New Tetracyclic Lactam Building Block for Thick, Broad-Bandgap Photovoltaics
Journal article, 2014

A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on π-stacking of the polymer backbone, which was retained in PTNT:fullerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 5% for >200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of >4% could be retained when thick active layers of 400 nm were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.

Author

Renee Kroon

University of South Australia

Chalmers, Chemical and Biological Engineering, Polymer Technology

Amaia Diaz de Zerio Mendaza

Chalmers, Chemical and Biological Engineering, Polymer Technology

Scott Himmelberger

Chalmers, Applied Physics

J. Bergqvist

Stanford University

Olof Bäcke

Chalmers, Applied Physics, Eva Olsson Group

Gregório Couto Faria

Stanford University

University of Sao Paulo (USP)

Feng Gao

Linköping University

Abdulmalik Obaid

Wake Forest University

Wenliu Zhuang

Chalmers, Chemical and Biological Engineering, Polymer Technology

Desta Antenehe Gedefaw

Chalmers, Chemical and Biological Engineering, Polymer Technology

Eva Olsson

Chalmers, Applied Physics, Eva Olsson Group

Olle Inganäs

Linköping University

Alberto Salleo

Stanford University

Christian Müller

Chalmers, Chemical and Biological Engineering, Polymer Technology

Mats Andersson

Chalmers, Chemical and Biological Engineering, Polymer Technology

Journal of the American Chemical Society

0002-7863 (ISSN) 1520-5126 (eISSN)

Vol. 136 33 11578-11581

Subject Categories

Polymer Chemistry

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Energy

Materials Science

DOI

10.1021/ja5051692

More information

Latest update

12/11/2018