Quantifying Dual-Direction Energy Harvesting in Twisted Perylene Nonfullerene Acceptor Organic Photovoltaics

Goldingay, A and Stuart, AN and Ghosh, P and Yadav, S and Gangadharappa, C and Patil, C and Rao, A and Lakhwani, G (2023) Quantifying Dual-Direction Energy Harvesting in Twisted Perylene Nonfullerene Acceptor Organic Photovoltaics. In: Journal of Physical Chemistry C, 127 (51). pp. 24598-24607.

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Abstract

Perylene monomers (PDIs) and twisted dimers (TPDIs) are investigated here as nonfullerene acceptors and are paired with the polymer donor PTB7-Th in organic photovoltaic blends. A combination of device characteristics, morphology studies, and transient absorption techniques reveals a complete picture of the photophysics in these two systems. TPDI-based devices are shown to far outperform PDI-based devices, and intensity-dependent JSC and VOC measurements reveal that they do not suffer from nongeminate recombination to the same extent as PDI-based devices. Transient absorption (TA) spectroscopy also demonstrates dual-direction energy harvesting from the excitation of both PTB7-Th and (T)PDI domains. TA reveals that charges live significantly longer in TPDI blends and are less susceptible to bimolecular recombination. The modeling of these processes allows for quantification of the relative contributions of each charge generation pathway. We find that TPDI-based devices benefit from a more balanced dual-direction charge generation process, which can be linked to the favorable morphology in the TPDI:PTB7-Th blend, demonstrating the critical importance of photoactive layer morphology considerations in the design of OPV acceptor materials. © 2023 American Chemical Society.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry C
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to Author.
Keywords:	Dimers; Morphology; Polycyclic aromatic hydrocarbons; Polymer blends; Transient absorption spectroscopy, Bimolecular recombination; Charge generation; Device characteristics; Device dependent; Intensity-dependent; Organic photovoltaics; Perylenes; Photophysics; Transient absorption; Transient absorption spectroscopies, Energy harvesting
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	01 Mar 2024 09:49
Last Modified:	01 Mar 2024 09:49
URI:	https://eprints.iisc.ac.in/id/eprint/84009

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