Yazar "Kocyigit, Adem" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Characterization of Al/In:ZnO/p-Si photodiodes for various In doped level to ZnO interfacial layers
    (ELSEVIER SCIENCE SA, 2018) Yildirim, Murat; Kocyigit, Adem
    The detection of the light by a device is so important for industrial applications such as energy harvesting, sensing and switching. For that aim, we have introduced various In doped (0%, 0.1%, 0.5% and 1.0%) nanostructure ZnO thin films which was prepared by the sol-gel spin coating technique as interfacial materials between the Al metal and p-type Si for investigation photodetection properties of the material. According to morphological results of the In doped ZnO thin films at AFM, undoped and In doped ZnO thin films formed as fiber like structures. The obtained optical band gap energy for undoped, 0.1%, 0.5% and 1.0% In doped ZnO thin films were determined as 3.293 eV, 3.283 eV, 3.272 eV and 3.263 eV, respectively. The Al/In:ZnO/p-Si devices were characterized with I-V and C-V measurements. The I-V data was acquired under various illumination conditions to see the response of the devices to the light. The I-V characteristics have revealed that the devices have high ideality factors and, their values usually increased with increasing In doping level, but the rectifying properties decreased. In addition, barrier heights and series resistance values decreased with increasing In doping level. Also, the device parameters were calculated via Cheung and Norde methods for accuracy of the results. The current transient measurements highlighted that In doping provided to increase of light response. The C-V measurements have imparted that the capacitance values are strong function of the frequency and voltage for various In doping level. The devices can be thought and improved as photodiode and photodetector applications in the industry. (C) 2018 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    A comparison of the electrical characteristics of TiO2/p-Si/Ag, GNR-TiO2/p-Si/Ag and MWCNT-TiO2/p-Si/Ag photodiodes
    (SPRINGER, 2019) Erdal, Mehmet Okan; Yildirim, Murat; Kocyigit, Adem
    The TiO2/p-Si/Ag, graphene nanoparticles doped (GNR) TiO2/p-Si/Ag and multi-walled carbon nanotube (MWCNT) doped TiO2/p-Si/Ag photodiodes were fabricated by electro-spinning technique at the same experimental conditions, and their structural, morphological and electrical properties were compared for photodiode applications. XRD measurements were confirmed undoped, GNR and MWCNT doped TiO2 structures, and brookite phase of (121) preferred orientation TiO2 has been observed from XRD patterns. SEM images of the heterojunctions showed that undoped and doped TiO2 layer have homogenous surfaces. I-V measurements were performed for electrical characterization of the TiO2/p-Si/Ag, GNR-TiO2/p-Si/Ag and MWCNT-TiO2/p-Si/Ag photodiodes under dark and light illumination conditions at room temperatures. The results imparted that all heterojunctions have good rectifying and photodiode properties. Some heterojunction parameters such as ideality factor, barrier height, series resistance were calculated and discussed in details according to thermionic emission theory, Cheung and Norde techniques. The determined ideality factor values are 8.55, 9.70 and 8.99, and barrier height values are 0.75 eV, 0.74 eV and 0.73 eV for the TiO2/p-Si/Ag, GNR-TiO2/p-Si/Ag and MWCNT-TiO2/p-Si/Ag photodiodes, respectively. These heterojunctions can be considered and improved as photodiodes in industrial applications.