Electrical analysis of Al/p-Si Schottky diode with titanium dioxide (TiO 2) thin film was performed at room temperature. The forward and reverse bias current-voltage (I-V) characteristics of diode were studied. Using thermionic emission (TE) theory, the main electrical parameters of the Al/TiO 2 /p-Si Schottky diode such as ideality factor (n), zero bias barrier height (φ Bo) and series resistance (R s) were estimated from forward bias I-V plots. At the same time, values of n, φ Bo and R s were obtained from Cheung's method. It was shown that electrical parameters obtained from TE theory and Cheung's method exhibit close agreement with each other. The reverse-bias leakage current mechanism of Al/TiO 2 /p-Si Schottky barrier diodes was investigated. The I-V curves in the reverse direction are taken and interpreted via both Schottky and Poole-Frenkel effects. Schottky effect was found to be dominant in the reverse direction. In addition, the capacitance-voltage (C-V) and conductance-voltage (G/w-V) characteristics of diode were investigated at different frequencies (50-500 kHz). The frequency dependence of interface states density was obtained from the Hill-Coleman method and the voltage dependence of interface states density was obtained from the high-low frequency capacitance method.

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Al2O3 insulator layer was deposited by atomic layer deposition (ALD) technique on p-type Si [Formula: see text] and the Al/Al2O3/p-Si metal/insulator/semiconductor (MIS) structures were fabricated. The current–voltage ([Formula: see text]) characteristics of these structures were investigated in two different temperatures. The main electrical parameters such as the ideality factor ([Formula: see text]), zero bias barrier height ([Formula: see text]), and series resistance ([Formula: see text]) values were found for 300 and 400[Formula: see text]K. The energy density distribution profiles of the interface state density ([Formula: see text]) were determined from the [Formula: see text] characteristics. In addition, the capacitance–voltage ([Formula: see text]) and conductance–voltage ([Formula: see text]) characteristics of devices were investigated in the frequency range 50–1000[Formula: see text]kHz at room temperature. Frequency-dependent electrical characteristics such as doping acceptor concentration ([Formula: see text]), energy difference between the valance band edge and bulk Fermi level ([Formula: see text]), diffusion potential ([Formula: see text]), barrier height ([Formula: see text]), the image force barrier lowering ([Formula: see text]), maximum electric field ([Formula: see text]), and [Formula: see text] values were determined using [Formula: see text] and [Formula: see text] plots. In addition, the [Formula: see text] values were performed using Hill–Coleman method. According to experimental results, the locations of [Formula: see text] and [Formula: see text] have an important effect on [Formula: see text], [Formula: see text] and [Formula: see text] plots of MIS structure.

In this study, semi-flexible dye-sensitized solar cell (DSSC) and flexible DSSC are examined comparatively. First, TiO2 paste with HCl was prepared and flexible photoanodes were produced by coating this paste on the indium tin oxide-coated poly(ethylene terephthalate) (ITO/PET) flexible substrates under the same conditions. These flexible photoanodes have been sensitized with Ruthenizer N719 dye at room temperature for 48[Formula: see text]h. The Pt was used as the back-electrode. The first back-electrode was fabricated for semi-flexible DSSC by spraying Pt on the fluorine-doped tin oxide (FTO). The second back-electrode was fabricated for flexible DSSC by coating Pt on ITO/PET using the chemical reduction method. The flexible photoanodes and Pt counter-electrodes have been combined. The photovoltaic performance of the semi-flexible DSSC was compared to the flexible DSSC.