| 1. |
- 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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| 2. |
- Li, Bo, et al.
(författare)
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Filamentary anemometry using femtosecond laser-extended electric discharge - FALED
- 2018
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Ingår i: Optics Express. - 1094-4087. ; 26:16, s. 21132-21140
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a non-contact spatiotemporally resolved comprehensive method for gas flow velocity field measurement: Filamentary Anemometry using femtosecond Laser-extended Electric Discharge (FALED). A faint thin plasma channel was generated in ambient air by focusing an 800-nm laser beam of 45 fs, which was used to ignite a pulsed electric discharge between two electrodes separated over 10 mm. The power supplier provided a maximum voltage up to 5 kV and was operated at a burst mode with a current duration of less than 20 ns and a pulse-to-pulse separation of 40 μs. The laser-guided thin filamentary discharge plasma column was blowing up perpendicularly by an air jet placed beneath in-between the two electrodes. Although the discharge pulse was short, the conductivity of the plasma channel was observed to sustain much longer, so that a sequence of discharge filaments was generated as the plasma channel being blown up by the jet flow. The sequential bright thin discharge filaments can be photographed using a household camera to calculate the flow velocity distribution of the jet flow. For a direct comparison, a flow field measurement using FLEET [Michael, Appl. Opt. 50, 5158 (2011)] was also performed. The results indicate that the FALED technique can provide instantaneous nonintrusive flow field velocity measurement with good accuracy.
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| 3. |
- Li, Xiaofeng, et al.
(författare)
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Enhancement of femtosecond laser-induced plasma fluorescence using a nanosecond laser
- 2019
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Ingår i: Optics Express. - 1094-4087. ; 27:4, s. 5755-5763
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the enhancement of femtosecond (fs) laser-induced filaments in air and nitrogen flow fields using a nanosecond (ns) laser. With the ns laser being imposed on the filaments, the length and the emission intensity of the filaments were largely increased. Temporally resolved spectra of the enhanced filaments were obtained. The results show that the ns laser enhanced the short-lifetime fluorescence of nitrogen, which comes from the transition processes of N 2 + (B 2 Σ u + - X 2 Σ g + ), N 2 (B 3 Π g - A 3 Σ u + ) and N 2 (C 3 Π u - B 3 Π g ). However, it had little effect on the long-lifetime chemiluminescence, which mainly comes from reactions such as N 2 (A 3 Σ u + ) + N 2 (A 3 Σ u + ) → N 2 (X 1 Σ g + , v = 0) + N 2 (B 3 Π g ). A possible explanation of this phenomenon is given, and this phenomenon might have potential applications in instantaneous one-dimensional measurements of various species in gas flow fields.
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| 4. |
- Liu, Peng-Fei, et al.
(författare)
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Hexagonal M2C3 (M = As, Sb, and Bi) monolayers : new functional materials with desirable band gaps and ultrahigh carrier mobility
- 2018
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry (RSC). - 2050-7526 .- 2050-7534. ; 6:46, s. 12689-12697
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Tidskriftsartikel (refereegranskat)abstract
- Based on first-principles calculations, we propose a new type of two-dimensional (2D) material M2C3 (M = As, Sb, and Bi) showing an infinite hexagonal lattice, in which C atoms adopt sp(2) hybridization and M atoms prefer three-fold coordination with lone pair electrons. Such monolayers are calculated to be stable verified by their moderate cohesive energies, the absence of imaginary modes in their phonon spectra, and the high melting points predicted via molecular dynamics simulations. Sb2C3 and Bi2C3 monolayers possess intrinsic band gaps of 1.58 and 1.23 eV (based on HSE06 calculations), values suitable for photovoltaic applications. The intrinsic acoustic-phonon-limited carrier mobility of the As2C3 sheet can reach up to 4.45 x 10(5) cm(2) V-1 s(-1) for electrons at room temperature, higher than that of (60-200 cm(2) V-1 s(-1)) MoS2 and (approximate to 10(3) cm(2) V-1 s(-1)) few-layer phosphorene, approaching the figure of merit in graphene (3 x 10(5) cm(2) V-1 s(-1)). The well-located band edge and visible light absorption make stretched Sb2C3 a potentially promising optoelectronic material for photocatalytic water splitting. Besides, Sb2C3/As2C3 excitonic solar cells have been proposed, and their power conversion efficiencies are estimated to exceed 23%. First-principles calculations have demonstrated that Sb2C3/Bi2C3 heterojunctions are indeed 2D node-line semimetals in the absence of spin-orbit coupling.
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| 5. |
- Xu, Chao, et al.
(författare)
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Stepwise assembly of a semiconducting coordination polymer [Cd8S(SPh)(14)(DMF)(bpy)](n) and its photodegradation of organic dyes
- 2015
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 44:14, s. 6400-6405
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Tidskriftsartikel (refereegranskat)abstract
- Chalcogenolate clusters can be interlinked with organic linkers into semiconducting coordination polymers with photocatalytic properties. Here, discrete clusters of Cd8S(SPh)(14)(DMF)(3) were interlinked with 4,4'-bipyridine into a one dimensional coordination polymer of [Cd8S(SPh)(14)(DMF)(bpy)](n) with helical chains. A stepwise mechanism for the assembly of the coordination polymer in DMF was revealed by an ex situ dynamic light scattering study. The cluster was electrostatically neutral and showed a penta-supertetrahedral structure. During the assembly each cluster was interlinked with two 4,4'-bipyridine molecules, which replaced the two terminal DMF molecules of the clusters. In their solid-state forms, the cluster and the coordination polymer were semiconductors with wide band gaps of 3.08 and 2.80 ev. They photocatalytically degraded rhodamine B and methylene blue in aqueous solutions. The moderate conditions used for the synthesis could allow for further in situ studies of the reaction-assembly of related clusters and coordination polymers.
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| 6. |
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