Second Generation of DiketopyrrolopyrroleDyes for NiO based Dye-Sensitized Solar Cells
2016 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, no 15, 7923-7940 p.Article in journal (Refereed) Published
In this study, four new diketopyrrolopyrrole (DPP) sensitizers, with a dicarboxylated triphenylamine anchoring group for attachment to NiO, were prepared and their electronic absorption, emission and electrochemical properties were recorded. The nature of the electronic excited-states was also modeled with TD-DFT quantum chemistry calculations. The photovoltaic performances of these new dyes were characterized in NiO-based dye-sensitized solar cells (DSCs) with the classical iodide/triiodide and cobaltII/III-polypyridine electrolytes, in which they proved to be quite active. Laser spectroscopy on dye/NiO/electrolyte films gave evidence for ultrafast hole injection into NiO (0.2-10 ps time scales). For the dyes with an appended naphtalenediimide (NDI) acceptor unit, ultrafast electron transfer to the NDI dramatically prolonged the lifetime of the charge separated state NiO(+)/dye-, from the ps time scale to an average lifetime ≈ 0.25 ms, which is among the slowest charge recombinations ever reported for dye/NiO systems. This allowed for efficient regeneration by CoIIIpolypyridine electrolytes, which translated into much improved PV-performance compared to the DPP dyes without appended NDI. Overall, these results underscore the suitability of DPP as sensitizers for NiO-based photoelectrochemical devices for photovoltaic and photocatalysis.
Place, publisher, year, edition, pages
2016. Vol. 120, no 15, 7923-7940 p.
IdentifiersURN: urn:nbn:se:uu:diva-280841DOI: 10.1021/acs.jpcc.5b12489ISI: 000374811100004OAI: oai:DiVA.org:uu-280841DiVA: diva2:912160
FunderEU, European Research Council, Marches -278845Knut and Alice Wallenberg FoundationSwedish Energy AgencySwedish Research Council