| 1. |
- Zhou, Haitao, et al.
(författare)
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New cyano-substituted organic dyes containing different electrophilic groups : aggregation-induced emission and large two-photon absorption cross section
- 2014
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 70:39, s. 7050-7056
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Tidskriftsartikel (refereegranskat)abstract
- Three aggregation-induced emission active dyes (3a-c) were synthesized and their one- and two-photon absorption properties have been investigated. They were all found to be weakly fluorescent in THF solution, while they exhibited dramatic fluorescence enhancement in water/THF mixtures. The solid fluorescence of 3a-c was recorded and their fluorescence quantum efficiency (Phi(F)) values were determined to be 8.0%, 8.1%, and 16.4%, respectively. Moreover, the two-photon absorption (2PA) cross-sections (sigma) of 3a-c were measured and 3a showed the highest value of 702 GM. The excellent aggregation-induced emission and 2PA properties provide a promising alternative for biophotonic materials.
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| 3. |
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| 4. |
- Li, Ruihuan, et al.
(författare)
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Effects of Cr and W additions on the stability and migration of He in bcc Fe : A first-principles study
- 2016
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Ingår i: Computational materials science. - : Elsevier. - 0927-0256 .- 1879-0801. ; 123, s. 85-92
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Tidskriftsartikel (refereegranskat)abstract
- Density functional theory calculations have been performed to study the effects of alloying Cr and W on the stability and diffusivity of interstitial He impurity in body-centered cubic (bcc) Fe host lattice. The interaction between two close Cr/W atoms is repulsive. The relative stable position for an interstitial He remains the tetrahedral interstitial site in the presence Cr. Energetically, He prefers to locate far away from W inside Fe host lattice due to the strong repulsive interaction between He and W. On the other hand, the He migration barrier becomes lower in the presence of Cr (0.026 eV) and W(0.049 eV), as compared to 0.059 eV for pure Fe. Addition of Cr is benefit for He self-trapping, while W is against. The effective diffusivity of He decreases with increasing Cr and W concentrations. Moreover, the additions of Cr and W slightly hinder He being trapped by monovacancy.
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| 5. |
- Cai, Shengyun, et al.
(författare)
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Photo-stable substituted dihydroindolo[2,3-b]carbazole-based organic dyes : tuning the photovoltaic properties by optimizing the pi structure for panchromatic DSSCs
- 2014
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 70:43, s. 8122-8128
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Tidskriftsartikel (refereegranskat)abstract
- Three dihydroindolo[2,3-b]carbazole (DDC) donor based organic dyes (DDC6-DDC8) with long conjugated systems were successfully synthesized and characterized by optical, electrochemical, computational analysis, and photovoltaic methods. It was found that the elongated pi system as well as the high molar extinction coefficients (4.2-5.3 M-1 cm(-1)) sufficiently reinforced the light harvesting ability with the IPCE response of one dye DDC8 extended to 850 nm, which resulted in large J(sc) of these dyes based devices (high as 16.41 mA cm(-2)). The attached alkyl chains suppress the dark current to some extent, resulting the DDC6 and DDC7 devices in high V-oc, while DDC8 displayed low V-oc, because BTD in DDC8 could attract the iodine ion, which could accelerate the charge recombination. Among the three dyes, DDC7 displayed the best performance with an eta value 6.53% under 4 mu m thick scattering layer (condition 1+1), which was boosted to 7.49% under 8 mu m thick scattering layer (condition 1+2). The photo-stability measurements indicated that all the three dyes are fairly photo-stable.
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| 6. |
- Chen, Wei, et al.
(författare)
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Highly sensitive detection of low-level water content in organic solvents and cyanide in aqueous media using novel solvatochromic AIEE fluorophores
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 5:16, s. 12191-12201
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Tidskriftsartikel (refereegranskat)abstract
- A great deal of effort has been devoted to develop easy-to-use fluorescent probes for detecting analytes due to their advantages in the field of chemo- and bio-sensing. Herein, two novel 2,2 '-biindenyl-based derivatives BDM and BDBM containing dicyanovinyl groups have been designed and synthesized, and are shown to possess the remarkable dual properties of solvatochromism and aggregation-induced emission enhancement (AIEE). Importantly, both of them are found to serve as fluorescent indicators for the qualitative and quantitative detection of low-level water in organic solvents. Meanwhile, both BDM and BDBM emit yellowish orange and orange fluorescence, respectively, in their aggregated states. Furthermore, with dicyanovinyl groups as the recognition sites, both compounds can act as colourimetric and fluorescent sensors for highly sensitive and selective detection of cyanide in aqueous media, and the apparent response signals can be observed by the naked eye even in the presence of various interference anions, promising practical applications for detecting cyanide in drinking water. Besides, optical spectroscopic techniques, NMR titration measurements, and density functional theory calculations are conducted to rationalize the sensing mechanisms of the two probes.
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| 7. |
- Chen, Xie, et al.
(författare)
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Climate change impacts on global photovoltaic variability
- 2024
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 374
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Tidskriftsartikel (refereegranskat)abstract
- The anticipated increase in the frequency of extreme weather events and the growing photovoltaic (PV) penetration in the energy system raise concerns about future variability in PV power generation. However, future changes in global PV variability based on the CMIP6 still remain uncertain. To fill this gap, data from 16 state-of-art CMIP6 models were employed to analyze trends in both PV power generation and variability for 2025–2100 under low, medium, and high greenhouse gas emission scenarios. A multivariate bias correction algorithm (MBCn) was used to calibrate CMIP6 data, with reanalysis data - ERA5 serving as the benchmark. Additionally, the impact of meteorological factors were examined. The results indicate that under the low emission scenario, global PV power generation shows a slight increase, while the other two scenarios exhibit decreasing trends. In terms of PV variability, changes are correlated with latitude, with high-latitude regions more likely to face higher fluctuations, leading to an additional approximately 16% of low-power days by 2100 under the high emission scenario. Furthermore, over two-thirds of the land area experiences a decrease in PV power generation along with increased variability under the high emission scenario, approximately 8 times higher than the low emission scenario. Considering the impact of meteorological factors, removing days with extreme high and low solar irradiance increases stability by about 23%. However, eliminating days with extreme high and low temperature worsens stability, revealing that global warming reduces variability to some extent due to the opposing effects of temperature and irradiance on PV power generation. This study highlights the consequences of climate change on PV power generation variability, providing valuable insights for PV installation planning, especially for countries at higher latitudes.
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| 8. |
- Huang, Wei, et al.
(författare)
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Propeller-like D-pi-A architectures : bright solid emitters with AIEE activity and large two-photon absorption
- 2014
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry (RSC). - 2050-7526 .- 2050-7534. ; 2:33, s. 6843-6849
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Tidskriftsartikel (refereegranskat)abstract
- Two novel molecules TABzPA and TATpPA with D-pi-A structure and large pi-conjugation have been synthesized via Wittig reaction. Unlike common molecules, which exhibit the aggregation-caused quenching (ACQ) phenomenon, TABzPA and TATpPA exhibit aggregation-induced emission enhancement (AIEE) activity: weak luminescence in common solvents but strong emission when aggregated as nanoparticles and solid powders. Due to their intramolecular charge transfer (ICT) attribution and AIEE features, TABzPA and TATpPA display bathochromic effects. Combining ICT and AIEE features, these molecules are intensely yellow solid emitters with high quantum efficiencies of about 23.2% and 24.1%. Moreover, TABzPA and TATpPA have excellent two-photon absorption (2PA) properties owing to good planarity and large pi-conjugation. The values of 2PA cross sections at 800 nm are 7590 GM and 7648 GM. The excellent optical properties of TABzPA and TATpPA pave the way for future potential applications in biophotonics and optoelectronics.
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| 9. |
- Shao, Cairu, et al.
(författare)
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Influence of Cr doping on the oxygen evolution potential of SnO2/Ti and Sb-SnO2/Ti electrodes
- 2019
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Ingår i: JOURNAL OF ELECTROANALYTICAL CHEMISTRY. - : ELSEVIER SCIENCE SA. - 1572-6657. ; 832, s. 436-443
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen evolution potential is the determining factor affecting the anode efficiency of the wastewater treatment process. In this study, we focus on increasing oxygen evolution potential of Cr-SnO2/Ti and Cr-Sb-SnO2/Ti electrodes with the pyrolytic method. XRD, SEM and XPS techniques had been applied to characterize the microstructures and chemical compositions of the samples. Electrochemical measurements had been performed to evaluate the oxygen evolution potential as a criterion of the wastewater treatment efficiency. The results show that co-doping of Sb and Cr improved the crystallinity and grain size of SnO2 coating, and Cr existed in the form of Cr(III) valence states. The Cr doping treatment improved the electronic conductivity and the electrocatalytic activity of the electrodes. DFT calculation of the band-structure indicates Cr doped SnO2 had a superior electrical conductivity, where Cr atom acts as an acceptor providing vacancies for electron transportation. The DOS diagrams reveal the Cr doped SnO2 showing a p-type conductivity which would subsequently influence the built-in potential on metal-semiconductor interface. We proposed the mechanism of the increase of oxygen evolution potential is the doping of Cr expands the built-in potential.
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| 10. |
- Tian, Guojian, et al.
(författare)
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A new D-A-pi-A type organic sensitizer based on substituted dihydroindolo [2,3-b] carbazole and DPP unit with a bulky branched alkyl chain for highly efficient DSCs
- 2015
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 3:7, s. 3777-3784
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Tidskriftsartikel (refereegranskat)abstract
- Two new D-A-pi-A configuration metal-free organic sensitizers (T1-T2) based on 5,7-dihexyl-6,12-diphenyl-5,7-dihydroindolo[2,3-b]carbazole and a DPP unit with a bulky branched alkyl chain have been synthesized for dye-sensitized solar cells. Due to a bulky branched alkyl chain being attached to the donor and DPP unit, both compounds obtain high V-oc values. Under standard global AM 1.5 solar light conditions, the T1 based-device gives a high conversion efficiency of 8.24% with a J(sc) of 15.72 mA cm(-2), a V-oc of 0.74 V and a FF of 0.71. These excellent performances make the donor dihydroindolo[2,3-b] carbazole and DPP unit promising candidates for further application in DSCs.
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