Yazar "Tunc, Tuncay" seçeneğine göre listele
Listeleniyor 1 - 2 / 2
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The Illumination Intensity and Applied Bias Voltage on Dielectric Properties of Au/Polyvinyl Alcohol (Co, Zn-Doped)/n-Si Schottky Barrier Diodes(WILEY-BLACKWELL, 2011) Uslu, Habibe; Altindal, Semsettin; Tunc, Tuncay; Uslu, Ibrahim; Mammadov, Tofig S.The Au/polyvinyl alcohol (PVA) (Co, Zndoped)/ n-Si Schottky barrier diodes (SBDs) were exposed to various illumination intensities. Illumination effect on the dielectric properties has been investigated by using capacitance- voltage (C-V) and conductance-voltage (G/omega-V) characteristics at 1 MHz and room temperature. The values of dielectric constant (epsilon'), dielectric loss (epsilon ''), loss tangent (tan delta), electric modulus (M' and M ''), and AC electrical conductivity (sigma(AC)) were found strongly intensity dependent on both the illumination levels and applied bias voltage especially in depletion and accumulation regions. Such bias and illumination dependency of these parameters can be explained on the basis of Maxwell-Wagner interfacial polarization and restructuring and reordering of charges at interface states. In addition, the epsilon'-V plots also show an intersection feature at similar to 2.8 V and such behavior of the epsilon'-V plots appears as an abnormality compared with the conventional behavior of an ideal SBD. The obtained results revealed that illumination intensity enhances the conductivity of Au/PVA(Co, Zndoped)/ n-Si SBD. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 322-328, 2011Öğe Synthesis and characterization of boron-doped Bi2O3-La2O3 fiber derived nanocomposite precursor(SPRINGER, 2011) Durmusoglu, Senol; Uslu, Ibrahim; Tunc, Tuncay; Keskin, Selda; Aytimur, Arda; Akdemir, AhmetBoron doped poly(vinyl) alcohol/ bismuth - lanthanum acetate (PVA/Bi-La) nanofibers were prepared by electrospinning using PVA as a precursor. The effect of boron doping was investigated in terms of solution properties, morphological changes and thermal characteristics. The fibers were characterized by FT-IR, XRD, SEM and BET. The addition of boron did not only increase the thermal stability of the fibers, but also their diameters, which yielded stronger fibers. XRD analyses showed that boron doping increased the peak intensities and indicated that the boron doping enhanced the crystallite size. Moreover, no shifts were noticed in diffraction angles for boron doped and undoped samples. Therefore, boron doping did not significantly alter the lattice spacing. The SEM micrograph of the fibers showed that the addition of boron resulted in the formation of cross linked bright surfaced fibers. Also, grain diameters of boron doped and undoped nanocrystalline sintered powders were measured as 170 nm and 120 nm respectively. The BET results show that boron undoped and doped Bi2O3-La2O3 nanocrystalline powder ceramic structures sintered at 800 A degrees C have surface areas of 20.44 m(2)/g and 12.93 m(2)/g, respectively.