Effect of the acceptor on the performance of dye-sensitized solar cells

Abstract

Three new phenothiazine dyes were designed and synthesized, utilizing different acceptor groups. Upon application to TiO2-based solar cells, the effects of different acceptors on the photophysical and electrochemical properties of the dyes and the solar cell performance are detailed. The introduction of a pyridinium unit or 5-carboxy-1-hexyl-2,3,3-trimethyl-indolium unit into the molecular frame as the acceptor instead of cyano acrylic acid can effectively cause a red shift in the absorption spectra. Applied to DSSCs, the devices sensitized by CM502 with the pyridinium unit as the acceptor show the highest efficiency of 7.3%. The devices fabricated with dye CM501 with cyano acrylic acid as the acceptor exhibited the highest Voc while for the devices sensitized by the dye CM503 with 5-carboxy-1-hexyl-2,3,3-trimethyl-3H-indolium unit as the acceptor, the Voc value was the lowest, at 494 mV. The addition of TBP in the electrolyte can improve the performance of DSSCs fabricated using CM501 and CM502, with the Voc value greatly improved but the Jsc value slightly decreased. However, with the addition of TBP in the electrolyte, the efficiency of the cells sensitized by CM503 dropped significantly (from 4.9% to 1.0% when 0.1 M TBP was added).

Density functional investigation and some optical experiments on dye-sensitized quantum dots

“…Our calculated V oc is in the range 2.3 -2.9 V (Table 6). To obtain an idea of the V oc values generally obtained, we note that the V oc for the thin film solar cells such as dye-sensitized solar cells [71][72][73] (in the cases where they have been calculated) or the experimental energy gap between the absorber and the acceptor 71,72,76 . This discrepancy is due to factors such as mismatch between energy levels, recombination losses, measuring method limitations and others.…”

Tuning Thiophene‐Based Phenothiazines for Stable Photocatalytic Hydrogen Production

“…In the H 2 productiono ver2 0h,t he new thiophenebased sensitizers revealed improved stabilityafter longerirradiation times and enhanced performances, in terms of H 2 productionr ates and light-to-fuel efficiencies,a fter an initial activation period, which weref or the first time associated with enhanced stability under photocatalytic production of H 2 and the absence of critical dye degradation. [21][22][23][24][25][26][27] Triggered by recent studies on phenothiazine (PTZ) derivatives as DSSC sensitizers [28][29][30][31] and by their first uses as light harvesters in the photo-driven productiono fH 2 , [32][33][34] we decided to systematically investigate this promising class of dyes by designing as eries of organic sensitizers containing the PTZ core as ad onor scaffold in donor-p-acceptor molecules. [14] Metal-freeo rganic sensitizers have gained an increasing role in the scientific literature of H 2 production, [15][16][17] with record DSSC powerc onversione fficiencies (PCE) exceeding1 2%.…”

“…[18][19][20] These dyes carry important advantages over metal complexes, such as easier and cheaper synthesis and purification, larger structural variety, and wider tunability of optical and energetic properties,w hich are fundamental to optimize the corresponding solar devices. [21][22][23][24][25][26][27] Triggered by recent studies on phenothiazine (PTZ) derivatives as DSSC sensitizers [28][29][30][31] and by their first uses as light harvesters in the photo-driven productiono fH 2 , [32][33][34] we decided to systematically investigate this promising class of dyes by designing as eries of organic sensitizers containing the PTZ core as ad onor scaffold in donor-p-acceptor molecules. Interestingly, av ery recent report on ac lass of benzo[b]phenothiazines confirms the increasing relevance of dye-sensitized H 2 production using organic dyes and PTZ derivatives.…”

Picolinic acid as an efficient tridentate anchoring group adsorbing at Lewis acid sites and Brønsted acid sites of the TiO2 surface in dye-sensitized solar cells

“…Researchers have developed many kinds of outstanding donors, such as triarylamine, diphenylamine, tetrahydroquinoline, phenothiazine, indoline and coumarin. [17][18][19][20] In DSSCs, the choice of suitable anchoring group was very important. The anchoring group determined the electron injection 40 rate and the binding energy of the dye on semiconductor surface.…”