Surfactant Engineering and Its Role in Determining the Performance of Nanoparticulate Organic Photovoltaic Devices

Riku Chowdhury; Natalie P Holmes; Nathan Cooling; Warwick J Belcher; Paul C Dastoor; Xiaojing Zhou

doi:10.1021/acsomega.1c05711

Surfactant Engineering and Its Role in Determining the Performance of Nanoparticulate Organic Photovoltaic Devices

ACS Omega. 2022 Mar 9;7(11):9212-9220. doi: 10.1021/acsomega.1c05711. eCollection 2022 Mar 22.

Authors

Riku Chowdhury¹, Natalie P Holmes², Nathan Cooling¹, Warwick J Belcher¹, Paul C Dastoor¹, Xiaojing Zhou¹

Affiliations

¹ Centre for Organic Electronics, College of Engineering, Science and Environment, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
² Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia.

Abstract

The fabrication of organic photovoltaics (OPVs) from non-hazardous nanoparticulate (NP) inks offers considerable promise for the development of eco-friendly large-scale printed solar modules. However, the typical NP core-shell morphology (driven by the different donor/acceptor affinities for the surfactant used in NP synthesis) currently hinders the photovoltaic performance. As such, surfactant engineering offers an elegant approach to synthesizing a more optimal intermixed NP morphology and hence an improved photovoltaic performance. In this work, the morphology of conventional sodium dodecyl sulfate (SDS) and 2-(3-thienyl) ethyloxybutylsulfonate (TEBS)-stabilized poly(3-hexylthiophene) (P3HT) donor:phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM) acceptor NPs is probed using scanning transmission X-ray microscopy, UV-vis spectroscopy, grazing-incidence X-ray diffraction, and scanning electron microscopy. While the SDS-stabilized NPs exhibit a size-independent core-shell morphology, this work reveals that TEBS-stabilized NPs deliver an intermixed morphology, the extent of which depends on the particle size. Consequently, by optimizing the TEBS-stabilized NP size and distribution, NP-OPV devices with a power conversion efficiency that is ∼50% higher on average than that of the corresponding SDS-based NP-OPV devices are produced.