The Effect of Pyridyl Nitrogen Atom Position in Pyrido-[3,4-b]pyrazines in Donor-Acceptor-pi-Acceptor Dyes on Absorption, Energy Levels, and Photovoltaic Performances of Dye-Sensitized Solar Cells
2016 (English)In: ASIAN JOURNAL OF ORGANIC CHEMISTRY, ISSN 2193-5807, Vol. 5, no 2, 293-300 p.Article in journal (Refereed) PublishedText
A donor-acceptor-pi-acceptor (D-A-pi-A)-type organic dye (DTN-1) incorporating a pyrido[3,4-b]pyrazine (PP) unit with the pyridyl N atom adjacent to the anchoring group has been synthesized for use in dye-sensitized solar cells (DSSCs). The maximum absorption wavelength of DTN-1 was clearly red-shifted compared with dye DT-1, based on PP unit with the pyridyl N atom adjacent to the donor group. However, this change of structure has a negative effect on photovoltaic performances, and devices made with DTN-1 only reached a power conversion efficiency of 6.10% under AM1.5G irradiation compared with 8.57% achieved by DT-1. Density functional theory calculations suggest that DTN-1 has a smaller oscillator strength, which is connected to its relatively low light-harvesting efficiency. In addition, the results of electrochemical impedance spectroscopy (EIS) reveal that charge recombination in DSSCs based on DTN-1 is more than that in the counterpart DT-1, thus leading to a lower open-circuit voltage (V-oc).
Place, publisher, year, edition, pages
Wiley-Blackwell, 2016. Vol. 5, no 2, 293-300 p.
donor-acceptor-pi-acceptor dyes, dye-sensitized solar cells, molecular engineering, nitrogen, pyrido[3, 4-b]pyrazines
IdentifiersURN: urn:nbn:se:kth:diva-183645DOI: 10.1002/ajoc.201500451ISI: 000370450600017ScopusID: 2-s2.0-84959537566OAI: oai:DiVA.org:kth-183645DiVA: diva2:913144
QC 201603192016-03-192016-03-182016-03-19Bibliographically approved