ICMCTF2012 Session PD-1: Post Deadline Discoveries and Innovations
Thursday, April 26, 2012 1:30 PM in Room Pacific Salon 1-2
PD-1-1 The Multi Beam Sputtering: a new thin film deposition approach
Pascal Sortais, T. Lamy, J. Médard (Laboratoire de Physique Subatomique et Cosmologie de Grenoble (LPSC), France)
Thanks to the latest development of ultra compact and reliable microwave ion sources1,2 it is now possible to build an ion beam sputterring system composed of an arbitrary large number of simple ion sources that can be individually tuned. With this new concept of Multi Beam Sputtering (MBS) device, new possibilities are conceivable for the Ion Beam Sputtering (IBS) technology3,4, especially for thin film deposition on large size substrates with high uniformity. With MBS, the deposition profile is not defined by the shape and the tuning of a unique large beam, but by the sum of the contributions of a great number of small, well controlled in size, sputterring spots. The uniformity is the consequence of the geometric sum of all sputterring lobes obtained by each sputtering spot. The ion sources units can be distributed along a circle or a line and each ion beam delivered by an ion source impinges its own target. An individual source of a typical size 3x3x3 cm uses a few watts of microwave power for producing a beam up to 1 mA with energy in the range of 5 to 15 keV. The first operational device, MBS-20, uses 20 of such ion sources distributed on a circle around a 70 mm diameter multi-target holder allowing thin film deposition on 100 to 300 mm diameter substrates with deposition rates in the range of 0 to 1 µm/h. An important point, since each ion source uses an individual target, is that co-evaporation of several components can be done simultaneously. By the way, the deposition of alloys with a controlled stoechiometry is easier than with any other method and without uniformity loss. We will show preliminary results for Cu, Ta, Ta2O5, C, Si02, Ti, TiN, TiO2, TiAlN and Th on 100 or 200 mm glass substrate diameters, Mylar 0.5 µm or Si substrates. All these processes can be done with reactive atmosphere allowing oxide or nitride deposition.
1P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81 (2010) 02B31
2P. Sortais, T. Lamy, J. Médard, J. Angot, P. Sudraud et al., Rev. Sci. Instrum. 83, 02B912 (2012
3Patent pending N° 1150981.
4Under Grant Grenoble Alpes Valorisation Innovation Technologies (GRAVIT) 080606, may 2009.
PD-1-2 Molecular dynamics simulation and experimental validation of nanoindentation measurements of silicon carbide coatings.
A.-P. Prskalo (Universität Stuttgart, Germany); Sven Ulrich (Karlsruhe Institute of Technology, Germany); S. Schmauder, J. Lichtenberg (Consultant); Carlos Ziebert (Kit, Iam-Awp, Germany)
Molecular dynamics simulation of the nanoindentation was used to investigate mechanical properties of single layer silicon carbide coatings on silicon substrates. Indenter load-penetration depth relation was determined and put into relation to the internal coating structure and the substrate behavior. In order to reach this objective, an indenter tip in the form of a Berkovich indenter was introduced, a discrete indenter motion of 0.2 Å was imposed. For the modeling of the Si-C system, well known bond-order Tersoff potential was used, while the substrate-indenter interaction was modeled by a self-developed short range repulsive pair potential. From the indenter load-penetration depth relation, mechanical values of hardness and Young modulus for the coatings could be obtained. Hardness values determined by molecular dynamics simulations were in the range between 26.4 GPa and 34.4 GPa. These results are in good agreement with experimental measurements using UMIS 2000 system delivering values between 20.1 GPa and 35 GPa in dependence of the micro structure of the coating, the deposition temperature and maximum indentation depth.
PD-1-3 Anatase TiO2 Beads Having Ultra-fast Electron Diffusion Rates for use in Low Temperature Flexible Dye-sensitized Solar Cells
Jyh-Ming Ting, Chun-Ren Ke (National Cheng Kung University, Taiwan)
The first use of mesoporous TiO2 beads in plastic substrate flexible dye-sensitized solar cell (FDSC) is demonstrated. Pure anatase TiO2 beads with various sizes (250 to 750 nm) and characteristics are obtained using a modified and efficient two-step method. The concept of chemical sintering, eliminating the step of additive removal, is used to prepare bead-containing paste for room temperature fabrication of photoanode having good adhesion to the substrate. The obtained photoanodes are examined for their dye loadings and light absorbance properties. Various plastic substrate FDSCs having commercial P25- and bead-containing photoanodes are fabricated and evaluated. The resulting cells are evaluated for the J-V characteristics, electron diffusion time, electron lifetime, charge-collection efficiency, electron-injection efficiency and incident photon-to-electron conversion efficiency. The bead-only cells not only have better efficiencies, as high as ~5%, but also exhibit ultra-fast electron diffusion rates, less than 1 ms. The best efficiency and electron diffusion rates are respectively 15% higher and two-order of magnitude faster than the P25-only cell. The effects of the bead characteristics on the cell performance is presented and discussed.
PD-1-6 Characterization of High Temperature Instrumented Indentation System and Initial Results
Vincent Jardret (Michalex, USA); Michel Fajfrowski (Michalex, France)
Abstract: High temperature instrumented indentation tests results are presented on a silicate glass sample at three temperatures; Room Temperature, 400oC and 600oC using the HTIIS 1000. This data is used to analyzed the thermal stability of the instrument, characterize key parameters such as load frame stiffness and indenter geometry, and finally determine the elastic and plastic properties of the sample at each temperature. The thermal management concept used in the instrument is described in details. A new method is proposed to identify the indenter shape using the shape of the curve √P versus h during the loading segment, and the ratio of √(P_max )⁄S_unload . The results show that the thermal management of the instrument provides very good stability during the tests. Tests with two different maximum loads enable a complete characterization of the instrument and the sample at high temperatures. This work will be pursued with the study of other materials and use of different indenter geometries and materials.