Enhanced Photovoltaic Efficiency via Control of Self-Assembly in Cyanopyridone-Based Oligothiophene Donors

Amanpreet Kaur Hundal; Salman Ali; Anubha Agarwal; Mohammed A Jameel; Lathe A Jones; Jing-Liang Li; Richard A Evans; Steven J Langford; Akhil Gupta

doi:10.1021/acs.jpclett.0c03526

Enhanced Photovoltaic Efficiency via Control of Self-Assembly in Cyanopyridone-Based Oligothiophene Donors

J Phys Chem Lett. 2021 Jan 21;12(2):919-924. doi: 10.1021/acs.jpclett.0c03526. Epub 2021 Jan 13.

Authors

Amanpreet Kaur Hundal¹, Salman Ali², Anubha Agarwal³, Mohammed A Jameel², Lathe A Jones¹, Jing-Liang Li⁴, Richard A Evans⁵, Steven J Langford², Akhil Gupta^{2

5}

Affiliations

¹ Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Science, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia.
² Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.
³ Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama, Tokyo 152-8550, Japan.
⁴ Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria 3216, Australia.
⁵ CSIRO Manufacturing, Bayview Avenue, Clayton South, Victoria 3169, Australia.

PMID: 33439648
DOI: 10.1021/acs.jpclett.0c03526

Abstract

The optoelectronic properties of functional π-conjugated organic materials are affected by their ability to self-assemble within thin films of devices. There are limited reports that demonstrate the positive impact of self-assembly on the photovoltaic performance of organic solar cells. Here, we demonstrate that hydrogen-bonded supramolecular arrays of a cyanopyridone-based oligothiophene donor, CP6, show notable improvement in photovoltaic performance upon self-assembly into a nanofibrous network. The honeycomb-like blend network exhibited higher hole mobility, leading to efficient charge generation and transport. The photovoltaic performance of CP6 was superior to that of two structural analogues, CP5 and CP1, and was attributed to the enhanced capability of CP6 to self-assemble into a film morphology favorable for BHJ devices. The BHJ devices comprising CP6 and the conventional fullerene acceptor (PC₇₁BM) exhibited an efficiency of 7.26%, which is greater than that of CP5 (5.19%) and CP1 (3.11%) and is among the best-performing, cyanopyridone-based oligothiophene donors described to date.