[6,6]‐Phenyl‐C61‐butyric acid methyl ester (PC61BM and PC71BM) is an archetypal electron acceptor in organic photovoltaic devices. However, it nucleates and grows to form aggregates or crystallites on a length scale of tens of nanometres to micrometres under thermal aging, which often results in a significant decrease in device efficiency and stability. To overcome this thermally induced performance degradation, many methods have been reported to date such as the introduction of hydrogen, halogen bonding, thermally or photochemically crosslinkable groups onto the fullerene, and the suppression of nucleation and growth of fullerene crystallites under thermal aging has been successfully demonstrated. Even though those methods are highly useful for the suppression of aggregation, we successfully demonstrated another one simple method for the same: Introduction of bulkier groups onto the fullerene, which can act as anchoring group to suppress the aggregation. In an extension of our previous work, quinoxaline (TQT), benzothiadiazole (TBTT) and benzoselenadiazole (TBST) based bulkier groups are linked to the fullerene, denoted as TQT‐C60, TBTT‐C60 and TBST‐C60, respectively, through the 1,3‐dipolar cycloaddition of corresponding azomethine ylides with fullerene. Single junction bulk heterojunction polymer solar cells were fabricated with the configuration ITO/PEDOT:PSS/P3HT:dyad/Ca/Al. The morphological stability of the active layer was monitored by transmission electron microscopy and optical microscopy. Independent of heteroatoms, all the dyads show excellent morphological stability under thermal aging compared to the archetypal acceptor PCBM due to the anchoring of substituent groups. © 2018 Society of Chemical Industry
Benzothiadiazole based diarylamine TBT-HH and its derivatives TBT-HN and TBT-HM, having an electron withdrawing nitro group and an electron donating methoxy group at para phenylamine position, respectively, were synthesized and used as a fluoride sensor. All the compounds show well-defined visible color changes in the presence of fluoride ion; the orange colour of TBT-HN becomes blue and the pink colored TBT-HH and TBT-HM becomes colourless. While the presence of Fred shifts the absorption maximum by 174 nm to the near IR region for comparatively electron deficient nitro substituent, for the electron rich receptors TBT-HH and TBT-HM blue shifted absorption was observed. 1 H-NMR titration experiments of all the receptors confirm deprotonation of the NÀ H proton by fluoride ion. The deprotonated state of the receptor was stabilized by electron withdrawing nitro substituent whereas that of electron donating substituents destabilizes the deprotonated state and subsequently leads to its decomposition, which is prevented by Cu 2 + ion through the complex formation. This hypothesis has been used to develop sensor strips based on these compounds, which shows a color change in the presence of fluoride ion in aqueous solution. Our investigations suggest that the presence of suitable electron deficient substitution would lead to the deprotonation of the diarlyamines, which can subsequently be used for several applications. In rare cases, fluoride induced decomposition of molecules can be prevented by this kind complex formation reaction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.