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Abstract: The development of new anchoring groups is important to facilitate effective co‐sensitization in dye‐sensitized solar cells (DSSCs). Herein, stable organic D–π–A dyes that contain new heterocyclic hydantoin‐based anchoring groups have been designed, synthesized, and used in DSSCs. These dye sensitizers were evaluated in terms of their absorption spectra, electrochemical properties, and performance in DSSC devices. Although only one‐third of the amount of hydantoin‐containing dyes adsorbed onto TiO2 relative to their cyanoacrylic‐acid‐containing analogues, they exhibited effective photoexcited electron‐transfer properties. External quantum efficiencies of over 80 % was observed, which were comparable to those of the cyanoacrylic‐acid‐containing dyes. In addition, the new hydantoin‐containing dyes exhibited significant robustness, which could allow improved stability of their corresponding photovoltaic devices under harsh conditions, such as high temperature and humidity. [ABSTRACT FROM AUTHOR]

Twenty-four D-A′-π-A dyes were rapidly synthesized through a one-pot three-component Suzuki-Miyaura coupling reaction, which was assisted by microwave irradiation. We measured the absorption spectra, electrochemical properties, and solar-cell performance of all the synthesized dyes. The D5 πA4 dye contained our originally designed rigid and nonplanar donor and exerted the highest efficiency at 5.4 %. The short-circuit current ( Jsc) was the most important parameter for the conversion efficiency ( η) in the case of the organic D-A′-π-A dyes. Optimal ranges for the D-A′-π-A dyes were observed for high values of Jsc/ λmax at λ=560-620 nm, an optical-absorption edge of λ=690-790 nm, and EHOMO and ELUMO values of <1.14 and −0.56 to −0.76 V, respectively. [ABSTRACT FROM AUTHOR]

We demonstrate herein the divergent synthesis of six dyes containing our originally developed rigid and nonplanar donor with three different secondary electron donors (SEDs), namely thiophene, 4-methoxybenzene, and diphenylethene. Evaluation of the photophysical properties of the synthesized dyes revealed that the introduction of the SEDs resulted in an increased absorbance in the 350-450 nm region. The influence of the SEDs on the electrochemical and photovoltaic properties depended on their structure and position of attachment. The introduction of the thiophene SED to D4π4A2, which we previously reported to be our best dye, resulted in an increased Jsc. The dye-sensitized solar cell (DSSC) prepared by using dye 2b, which contains the thiophene SED, shows a higher power conversion efficiency (PCE; η = 4.62 ± 0.02 %) and a higher incident photon-to-current conversion efficiency (IPCE) in the region 300-600 nm than D4π4A2. [ABSTRACT FROM AUTHOR]

This one-pot, four-component coupling approach (Suzuki-Miyaura coupling/CH direct arylation/Knoevenagel condensation) was developed for the rapid synthesis of thiophene-based organic dyes for dye-sensitized solar cells (DSSCs). Seven thiophene-based, organic dyes of various donor structures with/without the use of a 3,4-ethylenedioxythiophene (EDOT) moiety were successfully synthesized in good yields based on a readily available thiophene boronic acid pinacol ester scaffold (one-pot, 3-step, 35-61 %). Evaluation of the photovoltaic properties of the solar cells that were prepared using the synthesized dyes revealed that the introduction of an EDOT structure beside a cyanoacrylic acid moiety improved the short-circuit current ( Jsc) while decreasing the fill factor ( FF). The donor structure significantly influenced the open-circuit voltage ( Voc), the FF, and the power conversion efficiency (PCE). The use of a n-hexyloxyphenyl amine donor, and our originally developed, rigid, and nonplanar donor, both promoted good cell performance ( η=5.2-5.6 %). [ABSTRACT FROM AUTHOR]

The creation of organic dyes with excellent high power conversion efficiency (PCE) is important for the further improvement of dye-sensitized solar cells. We wish to describe the rapid synthesis of a 112-membered donor-π-acceptor dye library by a one-pot procedure, evaluation of PCEs, and elucidation of structure-property relationships. No obvious correlations between ε, and the η were observed, whereas the HOMO and LUMO levels of the dyes were critical for η. The dyes with a more positive EHOMO, and with an ELUMO<−0.80 V, exerted higher PCEs. The proper driving forces were crucial for a high Jsc, and it was the most important parameter for a high η. The above criteria of EHOMO and ELUMO should be useful for creating high PCE dyes; nevertheless, that was not sufficient for identifying the best combination of donor, π, and acceptor blocks. Combinatorial synthesis and evaluation was important for identifying the best dye. [ABSTRACT FROM AUTHOR]