Şükrü Karataş

Current-voltage and capacitance-voltage characteristics of Sn/rhodamine-101/n-Si and Sn/rhodamine-101/p-Si Schottky barrier diodes

The nonpolymeric organic compound rhodamine-101 (Rh101) film on a n-type Si or p-type Si substrate has been formed by means of the evaporation process and the Sn/rhodamine-101/Si contacts have been fabricated. The Sn∕Rh101∕n-Si and Sn∕Rh101∕p-Si contacts have rectifying contact behavior with the barrier height (BH) values of 0.714 and 0.827eV, and with ideality factor values of 2.720 and 2.783 obtained from their forward bias current-voltage (I-V) characteristics at room temperature, respectively. It has been seen that the BH value of 0.827eV obtained for the Sn∕Rh101∕p-Si contact is significantly larger than BH values of the conventional Sn∕p-Si Schottky diodes and metal/interfacial layer/Si contacts. Thus, modification of the interfacial potential barrier for metal/Si diodes has been achieved using a thin interlayer of the Rh101 organic semiconductor; this has been ascribed to the fact that the Rh101 interlayer increases the effective barrier height by influencing the space charge region of Si.The nonpolymeric organic compound rhodamine-101 (Rh101) film on a n-type Si or p-type Si substrate has been formed by means of the evaporation process and the Sn/rhodamine-101/Si contacts have been fabricated. The Sn∕Rh101∕n-Si and Sn∕Rh101∕p-Si contacts have rectifying contact behavior with the barrier height (BH) values of 0.714 and 0.827eV, and with ideality factor values of 2.720 and 2.783 obtained from their forward bias current-voltage (I-V) characteristics at room temperature, respectively. It has been seen that the BH value of 0.827eV obtained for the Sn∕Rh101∕p-Si contact is significantly larger than BH values of the conventional Sn∕p-Si Schottky diodes and metal/interfacial layer/Si contacts. Thus, modification of the interfacial potential barrier for metal/Si diodes has been achieved using a thin interlayer of the Rh101 organic semiconductor; this has been ascribed to the fact that the Rh101 interlayer increases the effective barrier height by influencing the space charge region of Si.

High Photoresponsivity Ru-doped ZnO/p-Si Heterojunction Diodes by the Sol-gel Method

The ruthenium (Ru) doped nanostructure ZnO films were prepared by the sol-gel spin coating method. Undoped and Ru doped ZnO films are formed as fibers. The optical band gaps of undoped, 0.1 at.% and 0.5 at.% Ru doped ZnO films were found to be 3.31, 3.30 and 3.29 eV, respectively. The electrical properties of undoped and Ru-doped ZnO/p-Si heterostructure diodes were investigated under dark and visible light illuminations using current–voltage (I–V) measurements. The diodes exhibit a non-ideal I–V behavior due to the interfacial layer and the series resistance. The electrical parameters such as ideality factors, barrier heights and series resistances obtained from different methods were determined under illumination conditions. The diode having 0.1 at.% Ru doped ZnO exhibited the highest photoresponse of 7.75 × 103 under 100 mW/cm 2. The obtained results indicate that the photoresponsivity properties of the ZnO based photodiode can be improved with Ru content.

Analysis of Current-Voltage-Temperature and Capacitance-Voltage-Temperature Characteristics of Re/n-Si Schottky Contacts

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 (σs) of 102 mV and 55 mV, respectively. Therefore, these values of the mean barrier height have been verified with the modified ln(I0/ T2) - q2σo2

The Analysis of the Electrical and Photovoltaic Properties of Cr/p-Si Structures Using Current-Voltage Measurements

q^{\mathrm {2}}{\sigma _{o}^{2}}

The investigation of the electromagnetic shielding effectiveness of multi-layered nanocomposite materials from reduced graphene oxide-doped P(AN-VAc) nanofiber mats/PP spunbond

/2 k2T2 vs (k T)−1 plot which belongs to two temperature sections.

Fully Automatic Soup Machine

In this work, the electrical and photovoltaic properties of Cr/p -Si structures were investigated using forward and reverse bias current-voltage (I - V ) measurements in dark and under illumination conditions (100 mW/cm2) at room temperature. The forward and reverse bias current–voltage (I - V ) characteristics of the Cr/p-Si structures were analyzed by the thermionic emission theory. For this, the main parameters such as ideality factors (n), barrier heights (Φbo), series resistances (RS), and reverse-saturation currents obtained from different methods using forward and reverse bias I - V measurements were investigated in under dark and illumination conditions at room temperature, respectively. Furthermore, the photovoltaic parameters such as short circuit current (Isc), open circuit voltage (Voc), fill factor (FF) and conversion efficiency (ηP) were acquired as 7.43 × 10-3 A/cm2, 0.260 V, 61.5% and 1.18% under 100 mW/cm2 light intensity, respectively, and these values are near to a photodiode. Experimental results show that all electrical parameters were found to be strong function of illumination density. Also, this result confirms that Cr/p-type-Si diode can be used as a photodiode in optoelectronic applications.

Temperature dependence of characteristic parameters of the H-terminated Sn/p-Si(1 0 0) Schottky contacts

In this study, the production of an electromagnetic shielding material by doping reduced graphene oxide was aimed. Graphene oxide was produced from graphite through modified Hummers method, and reduced graphene oxide was obtained by reducing graphene oxide. The reduced graphene oxide- doped poly(acrylonitrile-co-vinyl acetate) nanofiber mats were spun on the Polypropylene spunbond fabrics by a multi-needle electrospinning device at different lap numbers. Multi-layered surface samples of spunbond/nanofiber mats were obtained via calendaring process after overlapping in different layer numbers. The electromagnetic shielding effectiveness (EMSE) of these samples was measured in the range of 0.03–1.5 GHz according to ASTM D4935 standard. The effects of the numbers of laps and layers on the electromagnetic shielding effectiveness of the mats were also investigated. It was found that electromagnetic shielding effectiveness is greatly affected by changing the numbers of laps and layers. Consequently, the highest electromagnetic shielding effectiveness value of 35.49 dB was obtained from the sample containing two layers of nanofiber mats, each of which consisted 50 laps of nanofibers.

Electrical transport characteristics of Sn/p-Si schottky contacts revealed from I-V-T and C-V-T measurements

Accepted: 05.04.2016 Fully automatic soup machine project is made for meeting hunger needs of people in emergency situations without any request from anyone. Compared to systems that only cup soup, there is a system which suitable for Turkish society, meet bowl of soup and bread needs, at the same time self cleaning, report the lack of materials to system over web or mail with system to be installed. The system is controlled from PLC over and have visual support with a operator panel. Also, it transfers necessary information to central system with GSM mode and fiber lines. The system is characterized in that self cleaning. It is thought to take place near the municipality and police stations buildings, in parks and schools to serve the people. PLC programming is designed with twin cat. System software is designed in codesys ST language. Mechanical materials used is selected in accordance with food. Fingerprint application which prevent multiple use in the same day is developed. Mechanical design is prepared with Solid Works. Also remote monitoring module is developed. This module is designed two kinds. First designed is a cloud application. Remote access is designed making IP routing with cloud application in Beckoff PLC system. On the other system is designed to access codesys software via modemforwarding on port. The movement of mechanical equipment is designed on servo motor and pneumatic. Two servo motors and rotary pneumatic activators are used. Servo motors is designed for bread units and rotary activators for soup preparation mechanism.