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Full-Text Articles in Physics
A Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cellsa Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cells, Amal M. Al-Kahlout, Hatem S. El-Ghamri, Naji Al Dahoudi, Taher M. El-Agez, Sofyan A. Taya, Monzir S. Abdel-Latif
A Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cellsa Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cells, Amal M. Al-Kahlout, Hatem S. El-Ghamri, Naji Al Dahoudi, Taher M. El-Agez, Sofyan A. Taya, Monzir S. Abdel-Latif
Turkish Journal of Physics
In this paper, dye-sensitized solar cells (DSSCs) were fabricated using a zinc oxide (ZnO) semiconducting layer and different synthetic dyes. Eight different synthetic dyes were used to fabricate the DSSCs. Nanocrystalline ZnO powder was coated on transparent conducting fluorine-doped tin oxide glass using the doctor blade method to form a thin layer. The absorption spectra of the synthetic dyes were investigated. DSSCs were characterized with $J$-$V$ characteristic curves. The parameters reflecting the cell performance were calculated. The results revealed that eosin Y dye corresponds to the highest conversion efficiency. The dependence of the sintering temperature and the thicknesses of the …
Annealing Effects Of Zno Thin Films On P-Si(100) Substrate Deposited By Pfcvad, Kamuran Kara, Ebru Şenadim Tüzemen, Ramazan Esen
Annealing Effects Of Zno Thin Films On P-Si(100) Substrate Deposited By Pfcvad, Kamuran Kara, Ebru Şenadim Tüzemen, Ramazan Esen
Turkish Journal of Physics
In this study, ZnO films were prepared on p-Si substrates using the pulsed filtered cathodic vacuum arc deposition (PFCVAD) method. We report the effect of annealing temperature on structural and optical properties. The crystallographic structure and the size of the crystallites in the films were studied by means of X-ray diffraction. The films had a weak peak (100) orientation at 2theta = sim 32°. X-ray diffraction analysis of the as-deposited ZnO and the film annealed at 850 °C showed a strong ZnO (002) diffraction peak centered at 34.1° and 34.5°, respectively. The (004) peak was seen for film annealed at …
Self-Assembled Nanocrystalline Zno Thin Film Transistor Performance Optimization For High Speed Applications, Burhan Bayraktaroglu, Kevin Leedy
Self-Assembled Nanocrystalline Zno Thin Film Transistor Performance Optimization For High Speed Applications, Burhan Bayraktaroglu, Kevin Leedy
Turkish Journal of Physics
ZnO nanocrystals grown at relatively low temperatures using various vacuum deposition techniques can yield semiconducting thin films of self-assembled nanocolumns 20-50 nm in diameter. Such films are suitable for the fabrication of high speed and transparent thin film transistors (TFTs). Unlike amorphous TFTs, the performance of ZnO transistors depends both on the crystal quality of nanocrystals and the electrical properties of boundary layers between them. We investigated the use of radio frequency sputtering, atomic layer deposition, and pulsed laser deposition techniques to fabricate self-assembled nanocrystalline thin films and determined the influence of deposition conditions on the performance of transistors. Device …
Optical Properties Of Zno/(Zn, Mg)O Quantum Wells, Thierry Bretagnon
Optical Properties Of Zno/(Zn, Mg)O Quantum Wells, Thierry Bretagnon
Turkish Journal of Physics
This paper reviews the optical properties of ZnO/(Zn, Mg)O single quantum wells grown by molecular beam epitaxy. Both heteroepitaxial quantum well growth along the polar c-direction and homoepitaxial quantum well growth on the nonpolar M plane cases are considered. The optical properties of these quantum wells are investigated by using reflectance, continuous wave photoluminescence, and time-resolved photoluminescence spectroscopies. The quantum-confined Stark effect dominates the properties of the excitons for polar quantum wells. The magnitude of the internal electric field that is induced by both spontaneous and piezoelectric polarizations is determined by comparing the experimental results with a variational calculation of …
Synthesis And Gas Sensor Applications Of Nanostructured Zno Grown At Low Temperatures, Oleg Lupan, Thierry Pauporte, Lee Chow
Synthesis And Gas Sensor Applications Of Nanostructured Zno Grown At Low Temperatures, Oleg Lupan, Thierry Pauporte, Lee Chow
Turkish Journal of Physics
ZnO nanoarchitecture-based nano- and microdevices came into the focus due to their multifunctional operation. In this work, we summarize cost-effective procedures to grow ZnO nano- and microstructures, namely hydrothermal growth and electrochemical deposition. These techniques allow the controllable growth of ZnO nano- and microarchitectures at relatively low temperatures, below 100 °C, and do not require sophisticated equipment. We report on technological details for synthesis of ZnO and its characterization and applications in different novel devices such as gas sensors. Nanosensors and microsensors were fabricated using a focused ion beam and by metal welding an individual nano- and microstructure to form …
Zno-Based Nanostructures For Diluted Magnetic Semiconductor, Millaty Mustaqima, Chunli Liu
Zno-Based Nanostructures For Diluted Magnetic Semiconductor, Millaty Mustaqima, Chunli Liu
Turkish Journal of Physics
Since the prediction by Dietl et al. in the year 2000, extensive research activities have been focused on the ZnO-based diluted magnetic materials (DMSs). Earlier works were mainly performed using bulk or thin film materials with transition-metal doping, and diverse magnetic properties including ferromagnetism, paramagnetism, and diamagnetism have been reported. Identifying the dominant mechanism of the ferromagnetic ordering and realizing reproducible ferromagnetism above room temperature have been the main research issues, but a consensus is still lacking even today. Recently, reports on ZnO nanostructures with ferromagnetic behavior have been growing due to the novel properties brought about by the high …
Electron Field Emission From Nanostructured Semiconductors Under Photo Illumination, Oktay Yilmazoglu, Anatoli Evtukh, Shihab Al-Daffaie, Jens-Peter Biethan, Dimitris Pavlidis, Vladimir Litovchenko, Hans L. Hartnagel
Electron Field Emission From Nanostructured Semiconductors Under Photo Illumination, Oktay Yilmazoglu, Anatoli Evtukh, Shihab Al-Daffaie, Jens-Peter Biethan, Dimitris Pavlidis, Vladimir Litovchenko, Hans L. Hartnagel
Turkish Journal of Physics
New device concepts and materials for the fabrication of compact high-frequency vacuum sources and micro-nano-integrated X-ray sources are of particular interest for broadband communication, security screening of packages and chemical materials, biomedical examination, and other applications. This article integrates results on GaN- and ZnO-based nano and self-assembled structures. They were used as field emitter tips for cold electron emission at high local electric fields as well as for photoassisted field emitters to generate bunched electrons directly from the emitter tip. The results on functional field emitters as cold electron sources will be presented. They are key elements for building, among …
Study Of Solid-State Stability Of The Zoto Binary System, Sandeep A. Waghuley
Study Of Solid-State Stability Of The Zoto Binary System, Sandeep A. Waghuley
Turkish Journal of Physics
The ZOTO binary system contains different compositions of zinc oxide (ZnO) and tin oxide (SnO_2). These are important semiconductors and have been intensively explored for various applications. SnO_2, ZnO, and different mole ratios (70:30, 40:60, 30:70, and 20:80 SnO_2:ZnO) of the ZOTO system were prepared through proper thermal treatment in powder form. The comparative solid-state stability was investigated using thermogravimetric and differential thermal analysis (TG-DTA). The stability study showed that the SnO_2 material absorbs much lower heat (Ea = -72.06 kJ/g mol) compared with ZnO and their compositions. Thus the SnO_2 material shows stability at near room temperature operation. The …
Effective Annealing Of Zno Thin Films Grown By Electrochemical Deposition Technique, Cevdet Coşkun, Harun Güney, Emre Gür, Sebahatti̇n Tüzemen
Effective Annealing Of Zno Thin Films Grown By Electrochemical Deposition Technique, Cevdet Coşkun, Harun Güney, Emre Gür, Sebahatti̇n Tüzemen
Turkish Journal of Physics
Wide and direct band gap ZnO thin films have been grown on conductive indium-tin-oxide (ITO) substrates by electrochemical deposition (ECD) technique using different growth parameters. High quality films in terms of crystallographic and optical characteristics have been obtained under a cathodic potential of -0.9 V; a pH of 5.2, using 0.1 M Zn(NO_3)_2 solution. Oxygen gas flow through the solution increased the growth rate and the quality of samples. Subsequent heat treatments at various temperatures for 30 minutes under dry N_2 gas flow show that the most suitable annealing temperature is 300 °C for these electrochemically deposited thin films on …
A Single Junction Barrier Model For Varistors, Mustapha Tioursi, Abdallah Chaouch
A Single Junction Barrier Model For Varistors, Mustapha Tioursi, Abdallah Chaouch
Turkish Journal of Physics
In this paper, we propose a simplified model that explains the experimental behaviour of the single junction barrier height in varistors. The equation obtained for the barrier height variation versus voltage contains all parameters that characterize the grain boundary and has no adjustable parameters. It allows us to describe the equilibrium state for each voltage level. From this model, it is concluded that the threshold voltage and the nonlinearity coefficient for a single junction barrier are strongly related to the unoccupied traps level at zero bias, when the barrier height at zero bias and the leakage current are related to …