Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

2005 - 20072

Settings

Publisher: search.filters.publisher.National Institute of OptoelectronicsSubject: search.filters.subject.Thin films

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Mgb2 Superconducting Thin Films Grown by Magnetron Sputtering
    (National Institute of Optoelectronics, 2007) Ulucan, Savaş; Okur, Salih; Okur, Salih; Özyüzer, Lütfi; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    In this study, we report the growth and properties of MgB2 thin films on polycrystalline Al2O3 substrates. A composite MgB2 target was produced by MgB2 and Mg powder mixing, using a hot pressing technique. MgB2 thin films were grown on Al 2O3 substrates by d.c. magnetron sputtering, without heating the substrate. To enhance the superconducting properties of the as-grown films and to increase the crystal quality, an ex-situ anneal process was applied. The crystal structure of the thin films was determined by X-ray diffraction. The resistivity versus temperature of the deposited MgB2 thin films was studied to examine the transition temperatures of the films under various magnetic fields. The effects of the annealing temperature and annealing time on the electrical properties of MgB2 thin films are revealed.
  • Conference Object
    Citation - WoS: 7
    Citation - Scopus: 10
    Sub-Bandgap Absorption Spectroscopy and Minority Carrier Transport Properties of Hydrogenated Microcrystalline Silicon Thin Films
    (National Institute of Optoelectronics, 2005) Güneş, Mehmet; Göktaş, Oktay; Güneş, Mehmet; Işık, Nebile; Carius, Reinhard; Okur, Salih; Finger, Friedhelm; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    Hydrogenated microcrystalline silicon thin films have been prepared using HW-CVD and VHF-PECVD techniques with different silane concentrations. The steady-state photoconductivity, dual beam photoconductivity, photothermal deflection spectroscopy and steady-state photocarrier grating (SSPG) methods have been used to investigate the optical and electronic properties of the films. Two different sub-bandgap absorption methods have been applied and analyzed to obtain a better insight into the electronic states involved. For some films, differences existed in the optical absorption spectra when the measurements were carried out through the film side and through the substrate side. In addition, for some films, fringe patterns remained on the spectrum after the calculation of the fringe free absorption spectrum, which indicates that structural inhomogeneities were present throughout the film. Finally, minority carrier diffusion lengths deduced from the SSPG measurements were investigated as a function of the crystalline volume fraction (I c RS) obtained from Raman spectroscopy. The longest diffusion lengths and lowest sub-bandgap absorption coefficients were obtained for films deposited in the region of the transition to the amorphous growth.