Enhancement of the photovoltaic performance in D3A porphyrin-based DSCs by incorporating an electron withdrawing triazole spacer. (8th February 2018)

• Record Type: Journal Article
• Authors: Nikolaou, Vasilis; Charisiadis, Asterios; Chalkiadaki, Sofia; Alexandropoulos, Ioannis; Pradhan, Sourava C.; Soman, Suraj; Panda, Manas K.; Coutsolelos, Athanassios G.
• Is Part Of: Polyhedron. Volume 140(2018)
• Page Start: 9
• Page End: 18
• Publication Date: 2018-02-08
• Subjects: DSCs -- Porphyrin dyes -- Electron-withdrawing unit -- Click chemistry -- CE & OCVD; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.09.024
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Two novel zinc-porphyrin derivatives (ZnP-3DoH-click-CNCOOH andZnP-3DoH-click-COOH ) bearing an electron withdrawing spacer between the porphyrin ring and each anchoring group, have been studied as sensitizers in DSCs. Following this strategy four-fold and eight-fold increase of the device performance was observed compared to their reference complexes (ZnP-3DoH-COOH andZnP-3DoH-CNCOOH ). Abstract: In this study, we report the preparation of two novel zinc-porphyrin derivatives (ZnP-3DoH-click-CNCOOH andZnP-3DoH-click-COOH ) and two reference compounds (ZnP-3DoH-CNCOOH andZnP-3DoH-COOH ) as sensitizers in dye-sensitized solar cells (DSCs). The photo-physical and electrochemical measurements along with the computational studies suggest that the four synthesized porphyrin derivatives exhibit appropriate light absorption characteristics as well as suitable molecular orbital levels for their use as sensitizers in DSCs. All the modified zinc-porphyrin complexes bear hexyloxy chains at the ortho -positions of their three phenyl rings and contain either a carboxylic or a cyanoacrylic acid as anchoring group. In the zinc-porphyrin derivativesZnP-3DoH-click-CNCOOH andZnP-3DoH-click-COOH, a spacer with an electron withdrawing unit was incorporated between the porphyrin ring and each anchoring group. More specifically, the triazole ring was used as a spacer since it is considered to be a highly efficient electron transfer bridge. In addition, the pentafluoro-phenyl ring was selected due to its strong electron withdrawing ability in both final derivatives (ZnP-3DoH-click-CNCOOH andZnP-3DoH-click-COOH ). Following this strategy, fourfold and eightfold increase of the device performance was observed regardingZnP-3DoH-click-CNCOOH andZnP-3DoH-click-COOH, respectively, when compared to the efficiencies achieved with the reference compounds (ZnP-3DoH-COOH andZnP-3DoH-CNCOOH ). A more detailed interpretation of the charge dynamics in these devices was carried out using charge extraction (CE) and open-circuit voltage decay (OCVD) measurements.