| 1. |
- Kallioinen, J, et al.
(författare)
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Photoinduced ultrafast dynamics of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films: The influence of sample preparation and experimental conditions
- 2004
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Ingår i: The Journal of Physical Chemistry Part B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 108:20, s. 6365-6373
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Tidskriftsartikel (refereegranskat)abstract
- In most of the previous ultrafast electron injection studies of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films, experimental conditions and sample preparation have been different from study to study and no studies of how the differences affect the observed dynamics have been reported. In the present paper, we have investigated the influence of such modifications. Pump photon density, environment of the sensitized film (solvent and air), and parameters of the film preparation (crystallinity and quality of the film) were varied in a systematic way and the obtained dynamics were compared to that of a well-defined reference sample: Ru(dcbpy)(2)(NCS)(2)-TiO2 in acetonitrile. In some cases, the induced changes in the dynamics were uncorrelated to the electron injection process. High pump photon density (not in the linear response region) and exposure of the sensitized film to air altered the picosecond-time- scale kinetics considerably, and the changes were attributed mostly to degradation of the dye. In other cases, changes in the measured kinetics were related to the electron injection processes: reducing the firing temperature of the nanocrystalline film or making the film via electron beam evaporation (EBE) resulted in a decrease of the overall crystallinity of the film, and the electron injection slowed. In the sensitized EBE films, in addition to an increased contribution of triplet excited-state electron injection, a new electron transfer (ET) process with a time constant of 200 fs was observed.
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| 2. |
- Likonen, J., et al.
(författare)
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Structural investigation of re-deposited layers in JET
- 2008
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Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 377:3, s. 486-491
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Tidskriftsartikel (refereegranskat)abstract
- JET Mk-II Gas Box divertor tiles exposed in 1998-2001 have been analysed with various ion beam techniques, secondary ion mass spectrometry (SIMS) and Raman spectroscopy. Inner divertor wall tiles removed in 2001 were covered with a duplex film. The inner layer was very rich in metallic impurities, with Be/C - 1 and H-isotopes only present at low concentrations. The outer layer contained higher concentrations of D than normal for plasma-facing surfaces in JET (D/C - 0.4), and Be/C - 0.14. Raman and SIMS analyses show that the deposited films on inner divertor tiles are hydrogenated amorphous carbon with low sp' fractions. The deposits have polymeric structure and low density. Both Raman scattering and SIMS indicate that films on inner divertor wall Tiles 1 and 3, and on floor Tile 4 have some differences in the chemical structure of the deposited films
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