Yazar "Gezgin, Serap Yigit" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim Yok
    Öğe
    Analysis of Current-Voltage-Temperature and Capacitance-Voltage-Temperature Characteristics of Re/n-Si Schottky Contacts
    (SPRINGER, 2018) Durmus, Haziret; Kilic, Hamdi Sukur; Gezgin, Serap Yigit; Karatas, Sukru
    The current-capacitance-voltage characteristics of Re/n-type Si Schottky contacts have been measured in the temperature range of 60-300 K by steps of 20 K. The ohmic and Schottky contacts are made by the Pulsed Laser Deposition (PLD) technique. The values of barrier heights, ideality factors and serial resistances have been found to be strongly temperature dependent. In short, the ideality factor decreased and the barrier height increased with increasing temperature, when the temperature-dependent (I-V) characteristics were analyzed on the basis of the thermionic emission (TE) theory. The experimental barrier height and ideality factor were plotted against (kT) (-1) which gives two slopes, one is over the 60-140 K region and the other is over the 160-300 K region presenting a double Gaussian distribution of barrier heights. Two Gaussian distribution analyses of the I-V characteristics of the Re/n-type Si Schottky barrier diodes gave the mean barrier heights of 0.812 and 0.473 eV and standard deviations (sigma (s) ) of 102 mV and 55 mV, respectively. Therefore, these values of the mean barrier height have been verified with the modified ln(I (0)/ T (2)) - /2 k (2) T (2) vs (k T)(-1) plot which belongs to two temperature sections.
  • Küçük Resim Yok
    Öğe
    An Investigation of Localised Surface Plasmon Resonance (LSPR) of Ag Nanoparticles Produced by Pulsed Laser Deposition (PLD) Technique
    (AMER INST PHYSICS, 2017) Gezgin, Serap Yigit; Kepceoglu, Abdullah; Kilic, Hamdi Sukur
    Noble metal nano-structures such as Ag, Cu, Au are used commonly to increase power conversion efficiency of the solar cell by using their surface plasmons. The plasmonic metal nanoparticles of Ag among others that have strong LSPR in near-UV range. They increase photon absorbance via embedding in the active semiconductor of the solar cell. Thin films of Ag are grown in the desired particle size and interparticle distance easily and at low cost by PLD technique. Ag nanoparticle thin films were grown on micro slide glass at 25-36 mJ laser pulse energies under by PLD using nsNd:YAG laser. The result of this work have been presented by carrying out UV-VIS and AFM analysis. It was concluded that a laser energy increases, the density and size of Ag-NPs arriving on the substrate increases, and the interparticle distance was decreases. Therefore, LSPR wavelength shifts towards to longer wavelength region.
  • Küçük Resim Yok
    Öğe
    Plasmonic Tuning of Gold Doped Thin Films for Layers of Photovoltaic Devices
    (AMER INST PHYSICS, 2016) Gezgin, Serap Yigit; Kilic, Hamdi Sukur; Kepceoglu, Abdullah; Bayir, Sercan; Nalbantoglu, Izzet Ercan; Toprak, Ahmet
    In order to increase the absorption rates in solar cells, increasing research activities on the plasmonic nanostructures are followed carefully. The plasmonic nanoparticles provides an important enhancement in the trapping of photons in the active layer of the solar cells by means of interaction between incident light and plasmonic nanoparticles. In order to obtain this approach, under of 5x10(-4) mbar and 1x10(-2) mbar ambient argon gas pressure, gold thin film was deposited on the silicon substrate by applying PLD system. The morphology of thin films obtained was investigated by AFM and SEM considering the effect of Ar gas pressure on the plasma plume. SPR peaks for Au nanoparticles deposited under 5x10(-4) mbar and 1x10(-2) mbar Ar gas pressure were observed at 756 nm and 658 nm wavelengths respectively. It has been stated that the SPR peak in the infrared is depend on the near field interaction between Au nanoparticles. Furthermore, when the pressure is increased to 1x10(-2) mbar Ar, it has been observed that the SPR peak for thin film is shifted towards to shorter wavelengths, and it has also been observed that the intensity of absorption peak is decreased.
  • Küçük Resim Yok
    Öğe
    Production and Characterization of Titanium (Ti), Platinum (Pt) and Tantalum (Ta) Thin Films for Native DNA Biosensors
    (AMER INST PHYSICS, 2017) Genc, Eminegul; Kepceoglu, Abdullah; Gezgin, Serap Yigit; Kars, Meltem Demirel; Kilic, Hamdi Sukur
    The use of the femtosecond (fs) laser pulses for ablation applications have several advantageous and Laser Induced Forward Transfer (LIFT) is an ablation-driven transfer process. The use of fs laser pulses for LIFT is gaining a great attraction nowadays. The most of the Direct Writing (DW) methods are laser based techniques and the LIFT technique is the one of them. This spectacular technique allows high resolution without lithographic processes. In this study, we have grown Ti, Pt and Ta thin films on the microscope slides by Pulse Laser Deposition (PLD) teclmique using Nd:YAG laser in the high vacuum condition. As a result, thin films produced in this work is a good candidate to produce native DNA biosensors based on LIFT teclmique.