DETERMINATION OF MAIN ELECTRICAL PARAMETERS OF Au-4H-n-SiC (MS) AND Au-Al2O3-4H-n-SiC (MIS) DEVICES

In this study, Au-4H-n-SiC metal-semiconductor (MS) and Au-Al2O3-4H-n-SiC metal-insulator-semiconductor (MIS) devices were fabricated to examine the effects on the performance of electronic devices of interfacial insulating materials. In order to determine the dielectric properties, capacitance/conductance-voltage (C/G-V) measurements were realized in a wide range of voltages (-3.0 V)-(11.0 V). Current-voltage (I-V) measurements to obtain the electric properties were realized at +/- 2:5V. Moreover, both the energy distributions of surface states (N-ss) and series resistance (R-s) were obtained from the C/G-V data. Obtained results provided that series resistance originating from interfacial layer (Al2O3) was more effective on the I-V and C/G-V characteristics which must be taken into account in the calculation of main electrical parameters. The rectification ratio (RR) and shunt resistance (R-sh) of the MIS device were almost 10(3) times greater than those of the MS structure. Using Al2O3 between Au and 4H-n-SiC also led to an increase in the value of barrier height (BH) and a decrease in the value of ideality factor (n). These results confirmed that Al2O3 layer leads to an increase in the performance of MS device with respect to low values of N-ss, reverse saturation current (I-0) and n and high values of RR, R-sh and BH.WOS:0006525878000022-s2.0-8510197897

Investigation of effects on dielectric properties of different doping concentrations of Au/Gr-PVA/p-Si structures at 0.1 and 1 MHz at room temperature

In order to improve and detailedly investigate the dielectric properties of polymer interfaces of Metal-Polymer-Semiconductor (MPS) structures, three types of MPS were fabricated by doping 1, 3 and 5% graphene (Gr) into the polyvinyl alcohol (PVA) interface material. Capacitance-Voltage (C-V) and Conductance-Voltage (G/omega-V) measurements were used to analyze the dielectric properties of three types of MPS. UsingC-Vand G/omega-V data, series resistance (R-s) affecting device performance and interface properties besides basic dielectric parameters of each structure such as both the real and imaginary components of complex dielectric constant (epsilon'and epsilon''), complex electrical modulus (M' and M''), loss tangent (tan delta), and ac electrical conductivity (sigma(ac)) were also calculated. The effect of graphene doping was examined for each parameter and obtained results were compared at both low (0.1 MHz) and high (1 MHz) frequencies. It was observed that epsilon and epsilon'' decreased with increasing graphene doping at both 0.1 and 1 MHz, while M' and M'' increased under same conditions. Moreover, both the M' and M'' vs V plots have two distinctive peaks between -2.0 V and 0.0 V due to a special density distribution of surface states between (Gr-PVA) and p-Si. The tan delta gradually increased with increasing graphene doping at only 0.1 MHz. As the doping ratio of graphene increases, the charge carriers in the structure generate more dipoles and create an earlier relaxation process. In other words, increasing the doping ratio helps to improve the series resistance effects in MPS structures. As a result, it was seen that the interfacial properties of MPS structures were improved by increasing the rate of graphene doping.Gazi University Scientific Research Center [GU-BAP.05/2019-26]All authors would like to thank Gazi University Scientific Research Center for the supports and contributions (Project No: GU-BAP.05/2019-26).WOS:0005593755000092-s2.0-8508936624

Investigation of the variation of dielectric properties by applying frequency and voltage to Al/(CdS-PVA)/p-Si structures

In this study, the effect of frequency and voltage on the dielectric properties of Al/(CdS-PVA)/p-Si structures prepared using cadmium sulfide (CdS)-polivinyl alcohol (PVA) interface material was investigated. For this purpose, real and imaginary permittivity (epsilon' and epsilon ''), dissipation factor (tan delta), ac electrical conduction mechanism (sigma(ac)), real and imaginary part of electric modulus (M' and M) were obtained by using capacitance-conductance (C-G/omega) measurements at frequency between 5kHz - 5MHz and at voltage between (-1V) - (+1V). All parameters were found to depend considerably on the frequency and voltage. epsilon' and epsilon '' reach higher values at low frequencies due to surface states (N-ss) which can easily monitor ac signal, dipolar polarization and interfacial polarization. Short-range mobility of charge carriers caused the increase of both electrical modulus and sigma(ac) with increasing frequency. Moreover, M '' exhibited a peak behavior which shifts to higher frequency with increasing voltage. Peak behavior could be ascribed to both decrease in polarization and surface states. (C) 2020 Elsevier B.V. All rights reserved.Duzce University BAP research ProjectsDuzce University [2017.07.02.567, 2013.07.02.204]; Gazi University Scientific Research ProjectGazi University [GU-BAP.05/2019-26]This work is supported by Duzce University BAP research Projects with 2017.07.02.567 and 2013.07.02.204 numbers and Gazi University Scientific Research Project. (Project Number: GU-BAP.05/2019-26).WOS:0005980677000062-s2.0-8509178775