| 1. |
- An, Jincheng, et al.
(författare)
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Fine-Tuning by Triple Bond of Carbazole Derivative Dyes to Obtain High Efficiency for Dye-Sensitized Solar Cells with Copper Electrolyte
- 2020
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Ingår i: ACS Applied Materials and Interfaces. - : NLM (Medline). - 1944-8244 .- 1944-8252. ; 12:41, s. 46397-46405
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Tidskriftsartikel (refereegranskat)abstract
- Three novel dyes consisting of a 5,8,15-tris(2-ethylhexyl)-8,15-dihydro-5H-benzo[1,2-b:3,4-b':6,5-b″]tricarbazole (BTC) electron-donating group and a 4,7-bis(4-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (BTBT) π-bridge with an anchoring group of phenyl carboxyl acid were synthesized and applied in dye-sensitized solar cells (DSCs).The AJ202 did not contain any triple bonds, the AJ201's ethynyl group was inserted between the BTC and BTBT units, and the AJ206's ethynyl group was introduced between the BTBT moiety and the anchor group. The inclusion and position of the ethynyl linkage in the sensitizer molecules significantly altered the electrochemical properties of these dyes, which can fine-tune the energy levels of the dyes. The best performing devices contained AJ206 as a sensitizer and a Cu(I/II) redox couple, which resulted in a power conversion efficiency (PCE) up to 10.8% under the standard AM 1.5 G illumination, which obtained PCEs higher than those from the devices that contained AJ201 (9.2%) and AJ202 (9.7%) under the same conditions. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of the sensitizers were tuned to be well-suited for the Cu(I/II) redox potential and the Fermi level of TiO2. The innovative synthesis of a tricarbazole-based donor moiety in a sensitizer used in combination with a Cu(I/II) redox couple has resulted in relatively high PCEs.
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| 2. |
- An, J., et al.
(författare)
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Supramolecular Co-adsorption on TiO2to enhance the efficiency of dye-sensitized solar cells
- 2021
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 9:23, s. 13697-13703
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Tidskriftsartikel (refereegranskat)abstract
- Three novel push-pull dyes, with carbazole donors, codedAJ502,TZ101andTZ102are synthesized and applied as co-sensitizers in dye-sensitized solar cells (DSSCs).TZ101andTZ102have similar structures except for two fluorine atoms introduced on the benzotriazole (BTZ) unit.AJ502shows a near-IR absorption spectrum that is suitable for co-sensitization withTZ101andTZ102. The co-sensitized DSSC device based onCO-1(AJ502 : TZ101= 3 : 4 (0.075 mM : 0.1 mM)) achieves a power conversion efficiency (PCE) of 10.3% under AM 1.5G irradiation, with 1.06 V open-circuit voltage (Voc), 13.75 mA cm−2short-circuit photocurrent density (Jsc), and 70.8% fill factor (FF), a significant improvement compared to the single dye, 6.0% forAJ502and 5.1% forTZ101with a copper(i/ii)-based redox electrolyte. A PCE of 8.9% is also obtained by devices based onCO-2(AJ502 : TZ102= 3 : 4). ForCO-1, the fluorine atoms inTZ101play a critical role by widening the active light capturing bands of bothTZ101andAJ502on the TiO2film whileTZ102andAJ502show weaker interaction under the same conditions. The UV-vis spectrum and Raman spectrum revealed thatAJ502can form supramolecules withTZ101andTZ102formed on the TiO2film.
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| 3. |
- An, Jincheng, et al.
(författare)
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Thiophene-fused carbazole derivative dyes for high-performance dye-sensitized solar cells
- 2021
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 88
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Tidskriftsartikel (refereegranskat)abstract
- Two novel dyes that are similar in chemical structure, except for different donor units, AJ301and AJ303 were synthesized, characterized and applied as sensitizers in dye-sensitized solar cells (DSSCs). Both dyes exhibited a wide absorption of visible sunlight. The introduction of fused rings on the donor unit of AJ303 presented an appropriate energy level, less recombination and longer electron lifetime to achieve a power conversion efficiency (PCE) of 10.2%, far above that achieved for AJ301 of 6.2% with a [Co(bpy)(3)](2+/3+)-based electrolyte under standard AM1.5G solar irradiation (100 mW cm(-2)). The DSSCs based on AJ303 and AJ301 with [Cu(tmby)(2)](2+/+)-based electrolyte showed a lower PCE of 8.2% and 5.4%, respectively. Therefore, the results indicated that the introduction of a fused-ring in the donor group is a meaningful synthetic strategy to improve the photovoltaic performance.
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| 4. |
- Cai, Bin, et al.
(författare)
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Unveiling the light soaking effects of the CsPbI3 perovskite solar cells
- 2020
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 472
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Tidskriftsartikel (refereegranskat)abstract
- Pure inorganic perovskite of CsPbI3 attracts great attentions due to its excellent thermal stability and more suitable bandgap for tandem solar cells. The power conversion efficiency (PCE) of CsPbI3 perovskite solar cells has swiftly increased to 19.03%. However, extensive researches on the material property and photovoltaic characterization are rather rare in the literatures. In this study, a remarkable light soaking effect is found in the CsPbI3 based perovskite solar cells as the PCE increases from 10.8% to 18.3% after 180 s soaking under AM 1.5G sunlight. Mechanisms behind this reproducible soaking effect have also been studied. It reveals that the depressed dark current caused by a stronger built-in field and the decreased defects density passivated by the photogenerated electrons result in the enhanced PCE after light soaking. Moreover, we carefully characterize that the supposed "HPbI3" should be "DMAPbI(3)" synthesized through anti-solvent vapor recrystallisation method.
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| 5. |
- Chang, Qingyan, et al.
(författare)
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Precursor engineering enables high-performance all-inorganic CsPbIBr2 perovskite solar cells with a record efficiency approaching 13%
- 2024
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Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 90, s. 16-22
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Tidskriftsartikel (refereegranskat)abstract
- All-inorganic CsPbIBr2 perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability. However, the deposition of high-quality solution-processed CsPbIBr2 perovskite films with large thicknesses remains challenging. Here, we develop a triple-component precursor (TCP) by employing lead bromide, lead iodide, and cesium bromide, to replace the most commonly used double-component precursor (DCP) consisting of lead bromide and cesium iodide. Remarkably, the TCP system significantly increases the solution concentration to 1.3 M, leading to a larger film thickness (∼390 nm) and enhanced light absorption. The resultant CsPbIBr2 films were evaluated in planar n-i-p structured solar cells, which exhibit a considerably higher optimal photocurrent density of 11.50 mA cm−2 in comparison to that of DCP-based devices (10.69 mA cm−2). By adopting an organic surface passivator, the maximum device efficiency using TCP is further boosted to a record efficiency of 12.8% for CsPbIBr2 perovskite solar cells.
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| 6. |
- Chen, C., et al.
(författare)
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Boosting Electrocatalytic Water Oxidation by Creating Defects and Lattice-Oxygen Active Sites on Ni-Fe Nanosheets
- 2020
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Ingår i: ChemSusChem. - : Wiley-VCH Verlag. - 1864-5631 .- 1864-564X. ; 13:18, s. 5067-5072
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Tidskriftsartikel (refereegranskat)abstract
- Layered nickel-iron oxide/hydroxide nanosheets have proven to be the most efficient catalyst for the water oxidation reaction. Introducing structural defects to the nanosheets is a particularly attractive method for increasing the number of active sites and tailoring the intrinsic electronic properties. Herein, defects were introduced on Ni−Fe nanosheets through sequentially electrodoping and dedoping the surface of the material with tetramethylammonium ions. The as-prepared defect-rich Ni−Fe nanosheets showed an enhanced catalytic performance for the oxygen evolution reaction (OER) compared with conventional NiFe layered double hydroxides (LDHs), exhibiting an overpotential of only 172 mV at the current density of 10 mA cm−2. The relationship between pH and OER activity indicated that the lattice oxygens participated in the catalytic OER process as active sites. This work provides new insights into the understanding of the structure-activity relationship of layered materials and helps to develop new methods to implement defects on such frameworks aided by organic molecules.
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| 7. |
- Deng, Zijian, et al.
(författare)
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Helical Copper Redox Mediator with Low Electron Recombination for Dye-Sensitized Solar Cells
- 2021
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 9:15, s. 5252-5259
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Tidskriftsartikel (refereegranskat)abstract
- Redox mediators play a major role in determining the photocurrent and photovoltage in dye-sensitized solar cells (DSSCs). Copper complexes are a good option for redox mediators but suffer from electron recombination. The traditional method is to add 4-(tert-butyl)pyridine (TBP) to the electrolyte, which is coordinated with the empty orbit of Ti, thereby slowing down the oxidized mediator's ability to capture electrons. However, this strategy will result in competitive coordination between the redox mediator and TBP, decreasing the stability of the device. In this study, two helical copper(I) complexes are synthesized and applied to TBP-free solar cells. La (1,3-bis(2,2'-bipyridin-6-yloxy)propane) and Lb (1,3-bis[(6'-methyl-2,2'-bipyridin-6-yl)oxy]propane) tend to form double-stranded helicates ([Cu-2(Ln)(2)](2+), n = a, b) rather than mononuclear complexes ([Cu(Ln)](+), n = a, b). To facilitate quantitative analysis of the complexes, Cu(I)Ln and Cu(II)Ln (n = a, b) are used as molecular formulae. (CuLa)-La-I and Cu(I)Lb are characterized by electrospray mass spectroscopy, H-1 NMR spectroscopy, and electrochemistry. J-V measurement shows that both V-oc and J(sc) increase with the increase of (CuLa)-La-I concentration (below 0.1 M), and the best power conversion efficiency is 8.2%. The relationship between Cu(I) concentration and recombination for further study was measured by IMVS.
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| 8. |
- Du, Jian, et al.
(författare)
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2D materials for solar fuels via artificial photosynthesis
- 2022
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Ingår i: National Science Review. - : Oxford University Press (OUP). - 2095-5138 .- 2053-714X. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- To accelerate the chemical processes of water splitting, CO2 reduction and N2 fixation in artificial photosynthetic systems, various strategies to improve the properties of 2D materials with catalysts are highlighted in this perspective.
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| 9. |
- Du, Jian, et al.
(författare)
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Metal-organic frameworks and their derivatives as electrocatalysts for the oxygen evolution reaction
- 2021
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Ingår i: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 0306-0012 .- 1460-4744. ; 50:4, s. 2663-2695
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Forskningsöversikt (refereegranskat)abstract
- Electrochemical water splitting is an appealing and promising approach for energy conversion and storage. As a key half-reaction of electricity-driven water splitting, the oxygen evolution reaction (OER) is a sluggish process due to the transfer of four protons and four electrons. Therefore, development of low-cost and robust OER electrocatalysts is of great importance for improving the efficiency of water splitting. Based on the merits of high surface area, rich pore structure, diverse composition and well-defined metal centers, metal-organic frameworks (MOFs) and their derivatives have been widely exploited as OER electrocatalysts. Herein, the current progress on MOFs and their derivatives for OER electrolysis is summarized, highlighting the design principle, synthetic methods and performance for MOF-based materials. In addition, the structure-performance relationships of MOFs and their derivatives toward the OER are discussed, providing valuable insights into rationally developing OER catalysts with high efficiency. The current scientific and technological challenges and future perspectives towards the purpose of sustainable industrial applications are addressed at the end.
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| 10. |
- Elawad, Mohammed, et al.
(författare)
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Ionic liquid doped organic hole transporting material for efficient and stable perovskite solar cells
- 2020
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Ingår i: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 586
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Tidskriftsartikel (refereegranskat)abstract
- As a hole transporting material (HTM), N2,N2,N2',N2',N7,N7,N7',N7'-octakis (4-methoxyphenyl) spiro [fluorene-9,9'-xanthene]-2,2',7,7'-tetraamine (X60) in mesoscopic perovskite solar cells (PSCs) has been widely utilized for substitution of the 2,2',7,7'-tetrakis (N,N-di-p-methoxyphenylamine)-9,9'-spiro-bi-fluorene (spiroOMeTAD). In this study, we have introduced an ionic liquid N-butyl-N'-(4-pyridylheptyl) imidazolium bis (trifluoromethane) sulfonamide (BuPyIm-TFSI) as a p-dopant to increase the hole conductivity and stability of the X60 based perovskite solar cells. As a result, based on the different concentrations of BuPyIm-TFSI in mesoscopic PSCs, the optimal condition (4.85 mM) showed the best power conversion efficiency (PCE) of 14.65%, which is extremely higher than the device without BuPyIm-TFSI. Moreover, the device based on X60: BuPyIm-TFSI composite HTM at ambient conditions with humidity of similar to 40% exhibited good PSCs performance with the long-term stability of 840 h. Hence, the use of BuPyIm-TFSI as a p-dopant for X60 played a significant role in enhancing the electrical properties, stability and efficiency of PSCs.
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