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  • Küçük Resim
    Öğe
    Synthesis of nickel nanoparticles-deposited strontium titanate nanocubes (Ni-STO) and heterojunction electrical applications over a wide temperature range
    (Elsevier, 2021) Taşyürek, Lütfi Bilal; Aydoğan, Şakir; Sevim, Melike; Çaldıran, Zakir
    In the present study, the structural properties of nickel nanoparticles-deposited strontium titanate nanocubes (Ni-STO) were examined by taking XRD, ICP-MS, TEM and SEM images. Temperature-dependent capacitance–voltage (C-V) and current–voltage (I-V) measurements were made for the electrical characterization of the Ni/Ni-STO/n-Si heterojunction devices produced. As the temperature increases from 80 K to 400 K, the ideality factor (n) decreases from 2.30 to 1.02 while barrier height (BH) increases from 0.27 eV to 0.80 eV. In the heterojunction device between Ni-STO and n-type Si, electrons can be captured at the Schottky barrier interface and recombinations can be reduced. Devices produced with Ni-STO material had a positive effect on performance compared to the devices produced with STO in previous studies. The electrical parameters obtained give compatible results as a function of temperature. Metal deposited STOs are potential candidates for temperature-dependent sensors and electrical devices.
  • Küçük Resim
    Öğe
    Temperature dependent electronic transport properties of heterojunctions formed between perovskite SrTiO3 nanocubes and silicon
    (Springer, 2020) Taşyürek, Lütfi Bilal; Aydoğan, Şakir; Sevim, Melike; Çaldıran, Zakir
    In this study, synthesized strontium titanate (SrTiO3) nanocubes were coated on n-Si semiconductor by spin coating to obtain a heterojunction device. Transmission electron microscopy image, scanning electron microscope image and x-ray diffraction patterns of thin film of SrTiO3 nanocubes coated on Si surface were taken for structural and morphological characterization of the material. The basic device parameters such as ideality factor (n) and barrier height (?b) values of the reference Ni/Si/Al metal–semiconductor diode and of the Ni/SrTiO3/n-Si/Al heterojunction devices were calculated with the thermionic emission (TE) theory. The n and ?b values of the reference Ni/n-Si/Al device were calculated as 1.93 and 0.60 eV, respectively at room temperature. On the other hand, lower n and higher ?b values of Ni/SrTiO3/n-Si/Al heterojunction device were calculated as 1.34 and 0.63 eV, respectively. With these results, the current–voltage (I–V) measurements of the heterojunction device in the 80–400 K range were taken and the n, ?b, series resistance (Rs) values were calculated depending on the temperature by using different methods such as TE, Cheung and Norde functions. It was observed that while the temperature values decreased, n and Rs values of the device increase and ?b value decreases. The results obtained showed that the charge transport system is compatible with TE. The device parameters calculated from the Cheung and Norde methods also showed similar changes depending on the temperature. However, since the calculation method is different according to the TE method, different values were obtained in the device parameters. In addition, the curve ?b and (1/n)?1 against (1/2kT) was observed in accordance with the double Gauss distribution of the barrier heights. It was seen that the reverse bias I–V characteristics of the Ni/SrTiO3/n-Si/Al can be used in thermal sensors applications.