| 1. |
- Chen, Yingying, et al.
(författare)
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Fluorenyl Indoline as an Efficient Electron Donor for Concerted Companion Dyes: Enhanced Light-Harvesting and Photocurrent
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 13:42, s. 49828-49839
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Tidskriftsartikel (refereegranskat)abstract
- Concerted companion dyes (CC dyes) like XW61 have been demonstrated to be an effective platform for developing efficient DSSCs. However, the moderated phenothiazine-based electron donor in XW61 results in unsatisfactory J(sc). To address this problem, a stronger fluorenyl indoline-based electron donor has been used to construct porphyrin dye XW68 and organic dyes Y1-Y2. The stronger electron-donating character of the fluorenyl indoline unit leads to an enhanced J(sc) value (20.48 mA.cm(-2)) for the individual dye XW68. On this basis, CC dyes XW69-XW70-C8 have been designed and synthesized by combining the frameworks of Y1 and Y2 with XW68. The complementary absorption characters of the porphyrin and the organic dye moieties lead to panchromatic absorption with a strong light-harvesting capability from 350 to 700 nm and the onset wavelength extended to ca. 840 nm in the IPCE curves. As a result, excellent J(sc) values have been achieved (>22 mA.cm(-2)). In addition to the advantages of high J(sc), bulky octyl groups have been introduced into the donor of XW70-C8 to reduce dye aggregation and suppress charge recombination. Finally, a highest PCE of 11.1% with a satisfactory J(sc) (22.25 mA.cm(-2)) and an enhanced V-oc (750 mV) has been achieved upon coadsorption of XW70-C8 with CDCA. In addition, the CC dye XW70-C8-based solar cells exhibit excellent long-term photostability. These results provide an effective method for rationally improving the photovoltaic behavior, especially the J(sc) of CC dyes, by introducing strong electron donor moieties with suitable substituents.
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| 2. |
- Zou, Jiazhi, et al.
(författare)
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Efficient Dye-Sensitized Solar Cells Based on a New Class of Doubly Concerted Companion Dyes
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:29, s. 33274-33284
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Tidskriftsartikel (refereegranskat)abstract
- To develop efficient dye-sensitized solar cells (DSSCs), concerted companion (CC) dyes XW60-XW63 constructed from the covalent linkage of a strapped porphyrin dye unit and an organic dye unit have been reported to exhibit panchromatic absorption and excellent photovoltaic performance. However, these CC dyes only afforded moderate V-OC values of ca. 763 mV, demonstrating relatively weak antiaggregation ability, which remains an obstacle for further enhancing the photovoltaic behavior. To address this problem, we herein develop porphyrin dyes XW77-XW80 with the macrocycles wrapped with alkoxy chains of various lengths (OC6H13-OC22H45) and the corresponding CC dyes XW81-XW84 containing these porphyrin dye units. Interestingly, the new CC dyes XW81-XW83 exhibit increasing V-OC from 745 to 784 mV with the chain lengths extended from C6 to C18, and a lowered V-OC of 762 mV was obtained for XW84 when the chain length was further extended to C22. As a result, XW83 afforded the highest PCE of 12.2%, which is, to the best of our knowledge, the record efficiency for the iodine electrolyte-based solar cells sensitized with a single dye. These results can be rationalized by the so-called doubly concerted companion (DCC) effects, that is, the two subdye units exhibit not only complementary absorption but also concerted antiaggregation with the long wrapping chains on the porphyrins unit simultaneously protecting the porphyrin macrocycle and the neighboring organic subdye unit, thus affording panchromatic absorption and strong antiaggregation and anticharge-recombination ability. These results provide a new approach for constructing a class of DCC dyes to achieve high-performance DSSCs without using any antiaggregating coadsorbent or absorption-enhancing cosensitizer.
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| 3. |
- Zou, Jiazhi, et al.
(författare)
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Porphyrins containing a tetraphenylethylene-substituted phenothiazine donor for fabricating efficient dye sensitized solar cells with high photovoltages
- 2022
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 10:3, s. 1320-1328
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Tidskriftsartikel (refereegranskat)abstract
- With the aim to enhance the photovoltages and efficiencies of dye sensitized solar cells (DSSCs) based on porphyrin dyes, a dialkoxy-substituted highly twisted tetraphenylethylene (TPE) moiety has been introduced into the donor unit of a porphyrin dye to suppress dye aggregation and charge recombination. Thus, based on our previously reported porphyrin dye XW43, a dialkoxy-TPE moiety has been introduced into the phenothiazine donor to afford XW71. Compared with the diethyleneglycol substituent in XW43, the bulkier dialkoxy-TPE unit in XW71 is more beneficial for suppressing charge recombination. The alkoxy chains on the TPE moieties in XW71 are extended outward from the molecule and folded toward the porphyrin macrocycle, respectively, favorable for suppressing dye aggregation and charge recombination. As a result, the V-OC was dramatically improved from 0.750 V (XW43) to 0.765 V (XW71). On this basis, the substituents surrounding the porphyrin macrocycle have been optimized to further improve the V-OC and the efficiencies. Thus, XW72 and XW73 have been synthesized by replacing the dodecyloxy moieties on the meso-phenyl substituents of XW71 with two diethyleneglycol (DEG) chains and double straps, respectively. As a result, XW72 and XW73 exhibit a gradually improved V-OC of 0.772 V and 0.777 V, respectively, and a high power conversion efficiency (PCE) of 11.0% has been achieved for XW73. Upon coadsorption and cosensitization, the efficiency can be further enhanced to an outstanding value of 12.3% for the XW73 + CDCA + XC3 system.
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