A comparison of carboxypyridine isomers as sensitizers for dye-sensitized solar cells: assessment of device efficiency and stability

Synthesis and Investigation of Solar‐Cell Photosensitizers Having a Fluorazone Backbone

“…Although the HOMO orbitals are mostly localized on the donor moiety in both dyes, and therefore have a comparable energy (in agreement with the results of cyclic voltammetry experiments, see above), the HOMO-1 orbitals extend mostly over the central tricyclic portion of the molecules, with a smaller contribution from the donor (a bit more pronounced in the case of HT157), and have an energy difference of around 0.2 eV. Frontier orbital energies and energy gaps for the dyes DF15, [26] HT157 and TA1314. Frontier orbital energies and energy gaps for the dyes DF15, [26] HT157 and TA1314.…”

“…As a consequence, the energy gap between the frontier orbitals is smaller for TA1314 that for HT157. [26] Finally, as briefly mentioned in the Introduction, it should be noted that a TD-DFT computational analysis was carried out also on the regioisomeric form of dye HT157, which features an "inverted" fluorazone core (reg-HT157, see Figure S3 in the Supporting Information). Solvent effects were included by using the polarizable continuum model (PCM).…”

Design and synthesis of organic sensitizers with enhanced anchoring stability in dye-sensitized solar cells

“…This observation is not surprising, considering that even the simple pyridine ring has been reported to serve as anchoring group [14]. Based on these observations, device stability tests were also conducted on larger area, transparent cells, which indeed showed that devices built using compounds DF13B and DF13C retained their efficiency after 930 h of continuous simulated solar irradiation at 50 °C [27]. A similar observation was also made by Grätzel and co-workers, who synthesized a series of very efficient porphirin sensitizers carrying pyridine-containing anchoring groups (Fig.…”

“…3) [27]. Furthermore, alkoxy chains on the triarylamine donor [28], were inserted on purpose, in order to minimize aggregation phenomena, often occurring with this class of molecules, as well as to red-shift and broaden the absorption spectra of the compounds.…”

Novel pyran based dyes for application in dye sensitized solar cells

“…An accelerated aging test was performed on the better performing dye P 1 : a standard DSSC was prepared and kept at 85 °C, in the dark, for 1224 h (51 days) [51]. The basic electrical parameters of the cell were periodically measured to check their variation during time.…”