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A comparative electric and dielectric properties of Al/p-Si structures with undoped and Co-doped interfacial PVA layer
(Elsevier Sci Ltd, 2014) Kaya, A.; Yucedag, I.; Tecimer, H.; Altindal, S.
In this study, Al/p-Si structures with undoped and Co-doped PVA interfacial layer called S-1 and S-2 were fabricated and their both electrical and dielectric properties were compared by using 300 kHz capacitance voltage (C-V) and conductance voltage (G/omega-V) measurements at room temperature. Experimental results show that both C and G or dielectric constant (epsilon'), dielectric loss (epsilon '') values were found as strongly function of applied bias voltage especially at inverse and accumulation bias regions. It was found that the value of R-5 considerably decreases with doping Co metal contrary to conductivity especially in the forward bias region. Such behavior can be attributed to the lack of free charges in pure PVA. The imaginary parr of dielectric modulus (M '') gives Two peaks for S-1 corresponding To enough reverse and forward biases and passes from a minimum at about zero bias. Also, it is clear That the minimum of The M '' for S-2 coincides with The maximum of The for S-1 at zero bias. As a result, Co-doped PVA considerable improved The performance of structure. In addition, loss Tangent. (tan delta), ac conductivity (sigma(ac)) and real part. of The electric modulus (M') were obtained and compared each other. (C) 2014 Elsevier Ltd. All rights reserved,
A comparative study on the electrical parameters of Au/n-Si Schottky diodes with and without interfacial (Ca1.9Pr0.1Co4Ox) layer
(World Scientific Publ Co Pte Ltd, 2016) Kaya, A.; Cetinkaya, H. G.; Altindal, S.; Uslu, I.
In order to compare the main electrical parameters such as ideality factor (n), barrier height (BH) (Phi(I-V)), series (R-s) and shunt (R-sh) resistances and energy density distribution profile of surface states (N-ss), the Au/n-Si (MS) Schottky diodes (SDs), with and without interfacial (Ca1.9Pr0.1Co4Ox) layer were obtained from the current Z voltage (I-V) measurements at room temperature. The other few electrical parameters such as Fermi energy level (E-F), BIT (Phi(C-V)), Re and voltage dependence of N-ss profile were also obtained from the capacitance voltage (C-V) measurements. The voltage dependence of N-ss profile has two distinctive peaks in the depletion region for two diodes and they were attributed to a particular distribution of N-ss located at metal semiconductor (MS) interface. All of these results have been investigated at room temperature and results have been compared with each other. Experimental results confirmed that interfacial (Ca1.9Pr0.1Co4Ox) layer enhanced diode performance in terms of rectifier rate (RR = I-F/I-R at +/- 3.4 V), N-ss (at 0.5 eV) and Rsh (-3.4 V) with values of 265, 5.38 x 10(13)eV(-1).cm(-2) and 7.87 x 10(4) Omega for MS type Schottky barrier diode and 2.56 x 10(6), 1.15 x 10(13) eV(-1).cm(-2) and 7.50 x 10(8) Omega for metal insulator semiconductor (MIS) type SBD, respectively. It is clear that the rectifying ratio of MIS type SBD is about 9660 times greater than MS type SBD. The value of barrier height (BIT) obtained from C-V data, is higher than the forward bias I-V data and it was attributed to the nature of measurements. These results confirmed that the interfacial (Ca1.9Pr0.1Co4Ox) layer has considerably improved the performance of SD.
Current-conduction mechanism in Au/n-4H-SiC Schottky barrier diodes
(Natl Inst Science Communication-Niscair, 2015) Kaya, A.; Sevgili, O.; Altindal, S.; Ozturk, M. K.
Au/n-4H-SiC Schottky barrier diodes (SBDs) were fabricated and their temperature and voltage dependence of saturation current (I-o), ideality factor (n), bather height (Phi(bo)), series and shunt resistances (R-s, R-th) values were obtained by using current-voltage (I-V) measurements in the temperature range 110-400 K. The values of I-0, n and Phi(bo) were found as 3.00x10(-14)A, 3.41 and 0.39. eV at 110 K and 7.75x10(-7)A, 1.64 and 0.90 eV at 400 K, respectively. The Phi(bo)-q/2kT plot was drawn to obtain an evidence of a Gaussian distribution (GD) of the bather heights (BHs). The mean BH ((Phi) over bar (bo)) and standard deviation (sigma(o)) values have been extracted from the intercept and slope of this plot is as 1.089 eV and 0.127 V, respectively. The (Phi) over bar (bo) and Richardson constant (A*) values were obtained from the modified Ln(I-o/T-2) -(q(2)sigma(2)(s)/2k(2)T(2)) versus q/kT plot as ;1.093 eV and 160.6 A.cm(-2)K(-2) which can be considered as close to the theoretical value 146 A.cm(-2)K(-2), respectively. Voltage dependent activation energy (E-a) value was also obtained from the In(I-o/T-2)-q1/kT and In(I-o/T-2)-qI/nkT plots in the voltage range 0.05-0.50 V with 0.05 V steps and it is found that it decreases with increasing voltage. The temperature dependence of I-V characteristics in Au/n-4H-SiC diodes can be successfully explained on the basis of a TB mechanism with GD of the BHs.
Current-transport mechanism in Au/V-doped PVC plus TCNQ/p-Si structures
(World Scientific Publ Co Pte Ltd, 2015) Tecimer, H.; Vural, O.; Kaya, A.; Altindal, S.
The forward and reverse bias current-voltage (I-V) characteristics of Au/V-doped polyvinyl chloride+Tetracyanoquino dimethane/porous silicon (PVC+TCNQ/p-Si) structures have been investigated in the temperature range of 160-340 K. The zero bias or apparent barrier height (BH) (Phi(ap) = Phi(Bo)) and ideality factor (n(ap) = n) were found strongly temperature dependent and the value of nap decreases, while the n(ap) increases with the increasing temperature. Also, the Phi(ap) versus T plot shows almost a straight line which has positive temperature coefficient and it is not in agreement with the negative temperature coefficient of ideal diode or forbidden bandgap of Si (alpha(Si) = -4.73x10(-4) eV/K). The high value of n cannot be explained only with respect to interfacial insulator layer and interface traps. In order to explain such behavior of Phi(ap) and nap with temperature, Phi(ap) Versus q/2kT plot was drawn and the mean value of ((Phi) over bar (Bo)) and standard deviation (sigma(s)) values found from the slope and intercept of this plot as 1.176 eV and 0.152 V, respectively. Thus, the modified (ln(I-o/T-2) - (q sigma(s))(2)/2(kT)(2) versus (q/kT) plot gives the (Phi) over bar (Bo) and effective Richardson constant A* as 1.115 eV and 31.94 A.(cm.K)(-2), respectively. This value of A* (= 31.94 A.(cm.K)(-2)) is very close to the theoretical value of 32 A.(cm.K)(-2) for p-Si. Therefore, the forward bias I-V-T characteristics confirmed that the current-transport mechanism (CTM) in Au/V-doped PVC+TCNQ/p-Si structures can be successfully explained in terms of the thermionic emission (TE) mechanism with a Gaussian distribution (GD) of BHs at around mean BH.
Electrical and dielectric properties of Au/1% graphene (GP)+Ca1.9Pr0.1Co4Ox doped poly(vinyl alcohol)/n-Si structures as function of temperature and voltage
(Canadian Science Publishing, 2015) Cetinkaya, H. G.; Kaya, A.; Altindal, S.; Kocyigit, S.
Electrical and dielectric properties of Au/1% graphene (GP)+Ca1.9Pr0.1Co4Ox doped poly(vinyl alcohol)/n-Si structures have been investigated using the admittance spectroscopy method in the temperature and voltage ranges of 160-300 K and -4-5 V, respectively. Experimental results show that both the main electrical and dielectric parameters, such as barrier height (Phi(b)), depletion layer width (W-d), series resistance (R-s) of structure, real and imaginary parts of dielectric constant (epsilon', epsilon '') and electric modulus (M' and M ''), tan delta, and AC conductivity (sigma(ac)) were found to be strong functions of temperature and applied bias voltage. M' and M '' versus V plots have a peak at about 1 V. While the peak position shifted towards negative biases, the magnitude of the peak decreases with increasing temperature. Such peak behavior in M' and M '' can be attributed to the existence of particular density distribution profile interface states at the interfacial layer-n-Si interface and their reordering and restructure under external electric field and interface polarization. These peaks also indicated that the Au/1% GP+Ca1.9Pr0.1Co4Ox doped poly(vinyl alcohol)/n-Si structure exhibits relaxation phenomena.
Energy density distribution profiles of surface states, relaxation time and capture cross-section in Au/n-type 4H-SiC SBDs by using admittance spectroscopy method
(World Scientific Publ Co Pte Ltd, 2014) Kaya, A.; Sevgili, O.; Altindal, S.
Au/n-type 4H-SiC diodes were fabricated and their electrical characteristics have been investigated by using the capacitance/conductance-voltage-frequency (C-V -f and G/w - V f) measurements method at room temperature. The main parameters such as the doping atoms (N-D), diffusion potential (V-D) and barrier height (Phi(B)(C-V)) values were obtained from the reverse bias C-2 - V plots for each frequency. C and G/omega values decrease with increasing frequency as almost exponential for each voltage and these changes in C and G/omega are considerably high at low frequencies due to the contribution of surface states (N-ss) to the measured C and G/omega. The resistivity (Ri) versus V plots were also obtained by using the C and G data and they exhibit an anomalous peak which is corresponding to the depletion region at each frequencies and its magnitude decreases with increasing frequency. The energy density distribution of N-ss and their relaxation time (tau) were obtained from the conductance method and they range from 1.53 x 10(14) eV(-1) cm(-2) to 1.03 x 10(14) eV(-1) cm(-2) and 1.29 x 10(-4) s to 3.35 x 10(-5) s, respectively, in the energy range of (0.585 - E-v) - (0.899 - E-v) eV. The voltage dependent of N-ss was also obtained from C-HF - C-LF method. The obtained value of N-ss is about 10(14) eV(-1) cm(-2) order and these values are suitable for an electronic device.
Frequency and voltage dependence of dielectric properties and electric modulus in Au/PVC + TCNQ/p-Si structure at room temperature
(Elsevier, 2014) Kaya, A.; Vural, O.; Tecimer, H.; Demirezen, S.; Altindal, S.
Au/PVC + TCNQ/p-Si structure was fabricated and real and imaginary parts of the dielectric constant (epsilon', epsilon ''), loss tangent (tan delta), and the real and imaginary parts of the electric modulus (M', M '') and ac conductivity (sigma(ac)) of this structure have been investigated in wide frequency a range of 1 kHz-5 MHz at room temperature. All of these parameters were found strong function of frequency and voltage especially in the inversion and depletion regions at low frequencies due to interfacial polarization and charges at interface states (N-ss). The decrease in epsilon' and epsilon '' with increasing frequency indicated that the interfacial dipoles have less time to orient themselves in the direction of the alternate field. While the value of M' increase with increasing frequency and reach a maximum, M '' shows a peak and the peak position shifts to higher frequency with increasing applied voltage. The ln(sigma(ac)) vs ln(omega) plot of the structure for 0.5 V has three linear regions (I, II and III) with different slopes which correspond to low, intermediate and high frequency ranges, respectively. Such behavior of ln(sigma(ac)) vs ln(omega) plot indicated that there are three different conduction mechanisms in the Au/PVC + TCNQ/p-Si structure at room temperature. (C) 2013 Elsevier B. V. All rights reserved.
On double exponential forward bias current-voltage (I-V) characteristics of Au/Ca3Co4Ga0.001Ox/n-Si/Au (MIS) type structures in temperature range of 80-340 K
(Taylor & Francis Ltd, 2015) Maril, E.; Altindal, S.; Kaya, A.; Kocyigit, S.; Uslu, I.
Current transport mechanisms (CTMs) of Au/Ca3Co4Ga0.001Ox/n-Si/Au (MIS) type structures were investigated using current-voltage (I-V) characteristics in the temperature range of 80-340K. Semilogarithmic I-V plots show two linear regions corresponding to low (0.075-0.250V) and moderate (0.27-0.70V) biases, respectively. Zero-bias barrier height (phi(B0)) was observed to increase with increase in the temperature, whereas opposite behaviour was observed for ideality factor (n). phi(B0) and (n(-1)-1) vesus q/2kT and phi(B0) versus n plots were drawn to get an evidence of Gaussian distribution (GD) of the barrier heights. These plots, too, show two linear regions corresponding to low (80-160K) and high (200-340K) temperature ranges (LTR and HTR), respectively. Mean value of barrier height ( [GRAPHICS] (B0)) and standard deviation (sigma(s)) were extracted from the intercept and slope of phi(B0) versus q/2kT plots for two linear regions as 0.382eV, 0.0060V for LTR and 0.850eV, 0.135V for HTR at low biases and 0.364eV, 0.0059V for LTR and 0.806eV, 0.132V for HTR at high biases, respectively. [GRAPHICS] (B0) and Richardson constant (A*) values were also obtained from the intercept and slope of the modified Richardson (Ln(I-o/T-2)-(q(2)sigma(2)(s)/2k(2)T(2)) versus q/kT) plots as 131.81 Acm(-2)K(-2), 0.381eV for LTR and 129.35 Acm(-2)K(-2), 0. 854eV for HTR at low biases and 148.01 Acm(-2)K(-2), 0.377eV for LTR and 143.77 Acm(-2)K(-2), 0.812eV for HTR at high biases, respectively. In conclusion, CTM in the structure can be successfully explained in terms of thermionic emission theory with the double GD of barrier heights.
On the analysis of the leakage current in Au/Ca3Co4Ga0.001Ox/n-Si structure in the temperature range of 80-340 K
(Elsevier Sci Ltd, 2015) Maril, E.; Kaya, A.; Kocyigit, S.; Altindal, S.
The temperature dependent reverse bias leakage current-voltage (I-r-V-r) of the Au/Ca3Co4Ga0.001Ox/n-Si structure has been investigated in the temperature range of 80-340 K. The Ln(J(r)/E-r) vs E-0.5 plots show straight lines with different slopes in the intermediate reverse bias voltages for each temperature. Both the intercepts B(T) and slopes m(T) values were obtained from these plots for each temperature. Their values vs q/kT plots were drawn and they show a linear behavior except for two low temperatures (80 and 120 K). The dielectric constant (epsilon(s)) of interfacial Ca3Co4Ga0.001Ox. layer and the barrier height (phi(t)) which is necessary electron emission from the trap values were found from the slope of these plots, respectively. Experimental results show that the I-r-V-r, characteristics can be well described by the electric field dependence so the dominant conduction mechanisms are either Frenkel-Poole emission (FPE) or Schottky emission (SE) in this structure. The es and phi(t) values were found as 3.1 and 37.1 meV, respectively. It is clear that the value of phi(t) is considerably low and the value of dielectric constant (3.1) is closed to the dielectric value conventional of SiO2 insulator layer. These results confirmed that the (Ca3Co4Ga0.001Ox) interfacial layer can be used instead of a conventional of SiO2 insulator layer in the terms of flexibility, easy production and low cost. (C) 2014 Elsevier Ltd. All rights reserved.
On the Anomalous Peak in the Forward Bias Capacitance and Dielectric Properties of the Al/Co-Doped (PVC plus TCNQ)/p-Si structures as Function of Temperature
(Amer Scientific Publishers, 2015) Yucedag, I.; Kaya, A.; Altindal, S.
The temperature and voltage dependence of electric and dielectric characteristics and ac electrical conductivity (sigma(ac)) of Al/Co-doped (PVC + TCNQ)/p-Si structure in the temperature range of 200-360 K and voltage range of (-4 V)-(9 V) have been investigated in detail by using experimental C-V and G/omega -V measurements at 500 kHz. The value of dielectric constant (epsilon'), dielectric loss (epsilon ''), dielectric loss tangent (tan delta), the real and imaginary parts of electric modulus (M' and M ''), and the sigma(ac) were strongly dependent applied bias voltage and temperature, especially in the depletion and accumulation regions. Such a behavior in these parameters can be explained on restructuring and reordering of charges at interface traps/states. The forward C-V plots exhibit an anomalous peak for each temperature and the peak position shift towards lower voltages with increasing temperature due to the particular density distribution of interface traps (D-it) and series resistance (Rs) of structure. Therefore the plots of dielectric properties and also sigma(ac) indicate two different behaviors before and after intersection point. Before this intersection point, while the values of the epsilon', epsilon '', and sigma(ac) increase, the tan delta decreases, after this intersection point, while the value of the epsilon', epsilon '', and sigma(ac) decrease, the tan delta increases. The ln (sigma(ac))-q/kT plot shows two linear regions both for the 2 V and 9 V which are corresponding to below room temperature (200-300 K) and above room temperature (320-360 K) and the corresponding activation energy (E-a) values were called as Ea((I)) and Ea((II)), respectively. Thus the E-a values were obtained from the slope of these Arrhenius plot as 182 meV and 4.7 meV for 2 V and 22 meV and 0.6 meV for 9 V, respectively.
On the frequency dependent negative dielectric constant behavior in Al/Co-doped (PVC plus TCNQ)/p-Si structures
(World Scientific Publ Co Pte Ltd, 2014) Yucedag, I.; Kaya, A.; Altindal, S.
The dielectric properties, electric modulus and ac electrical conductivity (sigma(ac)) of Al/Co-doped (PVC + TCNQ)/p-Si structures have been investigated in the wide frequency and voltage range of 0.5 kHz-3 MHz and (-4 V)-( 9 V), respectively, using the capacitance-voltage (C-V) and conductance-voltage (G/omega-V) measurements at room temperature. The real and imaginary parts of dielectric constant (epsilon ', epsilon ''), loss tangent (tan delta), sigma(ac) and the real and imaginary parts of electric modulus (M ', M '') were found strongly function of frequency and applied voltage especially at low frequencies. The epsilon '-V plot shows an anomalous peak in the forward bias region due to the series resistance (R-s), surface states (N-ss) and interfacial layer (PVC + TCNQ) effects for each frequency and then it goes to negative values known as negative dielectric constant (NDC) at low frequencies (f <= 70 kHz). Such observation of NDC is important result because it implies that an increment of bias voltage produces a decrease in the charge on the electrodes. The amount of negativity epsilon ' value increases with decreasing frequency and this decrement in the NDC corresponds to the increment in the epsilon ''.
On the temperature dependent forward bias current-voltage (I-V) characteristics in Au/2% graphene-cobalt doped (Ca3Co4Ga0.001Ox)/n-Si structure
(Elsevier Sci Ltd, 2015) Maril, E.; Kaya, A.; Cetinkaya, H. G.; Kocyigit, S.; Altindal, S.
In order to good interpret of temperature dependent main electrical parameters in Au/2% graphene-cobalt (GC) doped (Ca3Co4Ga0.001Ox)/n-Si structure, forward bias current-voltage (I-V) characteristics have been investigated in the temperature range of 80340 K. The possible current-conduction mechanisms (CCMs) in this structure was also investigate in detail. The ideality factor (n), reverse saturation current (I-o), and zero-bias barrier height (Phi(Bo)) values were found as 14.5, 7.2 x 10(-6) A, 0.141 eV at 80K and 3.18, 1.7 x 10(-3) A, and 0.526 eV at 340 K, respectively. It is clear that both the value of n and Phi(Bo) are strong function of temperature. While the value of n decreases with increasing temperature, Phi(Bo) increases. In order to explain such behavior of BH the Phi(Bo) and n, Phi(Bo) vs q/2kT, Phi(Bo) vs n, and (n(-1)-1) vs q/2kT plots were drawn to obtain an evidence of a Gaussian distribution (GD) of the BHs and it shows a straight line. The mean value of BH ((Phi) over bar (Bo)) and standard deviation (sigma(s)) were found from the slope and intercept of this plot as 0.614 eV and 0.088 V, respectively. By using the modified Richardson plot, the (Phi) over bar (Bo) and Richardson constant (A*) values were obtained from the slope and intercept of this plot as 0.604 eV and 108.23 A cm(-2) K-2, respectively. It is clear that this value of A* ( = 108.23 A cm(-2) K-2) is very close to the theoretical value 112 A cm(-2) K-2 for n-Si. In conclusion, the temperature dependence of the forward bias I-V characteristics of the structure can be successfully explained on the basis of a thermionic emission (TE) mechanism with GD of the BHs. (C) 2015 Elsevier Ltd. All rights reserved.
Temperature and voltage dependences of dielectric properties and ac electrical conductivity in Au/PVC plus TCNQ/p-Si structures
(Elsevier Sci Ltd, 2014) Yucedag, I.; Kaya, A.; Tecimer, H.; Altindal, S.
Dielectric properties and ac conductivity (sigma(ac)) of Au/PVC+TCNQ/p-Si structures have been investigated in the wide temperature range of 80-420 K using capacitance-voltage (C-V) and conductance-voltage (G/omega-V) measurements at 1 MlHz. It has been found that the forward bias C-V plots exhibit a distinct peak especially at a high temperature. Effects of the series resistance (R-s), interfacial PVC+TCNQ layer and the density distribution of interfaces'traps (D-it) on the electrical peak and the dielectric properties were investigated in detail. All of the dielectric properties such as the real and imaginary parts of dielectric constants (epsilon', epsilon''), electric moduli (M' and M), loss tangent (tan delta), and sigma(ac), values were found to be strong functions of temperature and applied bias voltage. These changes become considerably high especially in the depletion region. In addition, the voltage dependent Rs values were obtained and they increased with decreasing temperature C-V-T and G/omega-V-T measurements confirmed that R-s, D-it, and PVC+TCNQ layers are very important parameters that strongly influence both dielectric properties and sigma(ac) of structures. (C) 2014 Elsevier Ltd. All rights reserved.
Temperature and Voltage Effect on Barrier Height and Ideality Factor in Au/PVC plus TCNQ/p-Si Structures
(Wiley-Hindawi, 2014) Kaya, A.; Demirezen, S.; Tecimer, H.; Altindal, S.
The forward bias current conduction mechanisms of Au/PVC + TCNQ/p-Si structures have been investigated in a wide temperature range of 120-420K for various applied bias voltage. The analysis of the main electrical parameters such as zero-bias barrier height (BH) (phi(Bo)), ideality factor (n), and interface states (N-ss) was found strongly dependent on temperature and voltage. The obtained results show that, while phi(Bo) increases, n decreases with increasing temperature. The plot of phi(app) versus q/2kT was drawn to show a Gaussian distribution (GD) of the BHs, and this plot shows two distinct linear regions. The phi(Bo) and standard deviation (sigma(s)) values were found from the slope and intercept of these plots for two regions as 1.16 eV and 0.161V for the first region and 0.71 eV and 0.093V for the second region, respectively. Such behavior is typical of a double GD (DGD) of the BHs due to the BH inhomogeneities at the metal-semiconductor interface. The slope and intercept of the modified (ln(I-0/T-2) - q(2)sigma(2)(0)/2k(2)T(2)) versus q/kT plot gives the and phi(Bo) and effective Richardson constant (A*) as 1.16 and 0.76 eV and 36.7 and 83.8 A/cm(2)K(2), respectively. The value of the A* (36.7 A/cm(2) K-2) is very close to the theoretical value of 32 A/cm(2) K-2 for p-Si. In addition, to interrupt the voltage-dependent activation energy, the ln(I-s/T-2) versus q/kT plot was drawn in the voltage range of 0-0.3V in 0.05V steps. All of experimental results confirmed that the BH or E-a values depend on the temperature as well as bias voltages.
The comparative electrical characteristics of Au/n-Si (MS) diodes with and without a 2% graphene cobalt-doped Ca3Co4Ga0.001Ox interfacial layer at room temperature
(Elsevier Science Bv, 2016) Kaya, A.; Maril, E.; Altindal, S.; Uslu, I.
To investigate the effect of 2% graphene cobalt (GC)-doped (Ca3Co4Ga0.001Ox) interfacial layer on the main electrical parameters, Au/n-Si (MS) Schottky barrier diodes (SBDs) were fabricated with and without this inter-facial layer. Using forward and reverse bias current-voltage (I-V) measurements, selected electrical parameters of these diodes were obtained and compared at room temperature. The energy density distribution profiles of the surface states (N) were obtained from the forward-bias I-V data by taking into account the voltage-dependent effective barrier height (be) and ideality factor (n(V)). The value of Ns, for the MPS-type diode is one order of magnitude lower than that of the MS diode. These results indicated that the 2% GC-doped (Ca(3)Co(4)Oa(0.001)O(x)) interfacial layer prevents reaction and inter-diffusion between Au and n-Si as well as passivating the active dangling bonds at the semiconductor surface. In addition, the voltage-dependent profile of the resistance (11,) was also obtained for the two diodes from the I-V data using Ohm's law. In both the MS- and MPS-type diodes, an apparent exponential increase in hl was observed from the mid-gap toward the bottom of the E. The experimental results show that the existence of Nss, Rs, and the interfacial layer has a great effect on the electrical characteristics of these structures. The value of the depletion layer width was obtained from C-V measurements at 300 kHz for the two diodes. The obtained results show that the GC-doped (Ca3Co4Ga0.001Ox) interfacial layer considerably enhances the diode performance. (C) 2015 Elsevier B.V. All rights reserved.
The effect of Mo-doped PVC plus TCNQ interfacial layer on the electrical properties of Au/PVC plus TCNQ/p-Si structures at room temperature
(Elsevier Sci Ltd, 2015) Demirezen, S.; Kaya, A.; Vural, O.; Altindal, S.
The effect of Mo-doped and undoped PVC+TCNQ interfacial layer on electrical characteristics of a Au/PVC+TCNQ/p-Si structure was investigated using current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G/omega-V) measurements at room temperature. The energy dependent interface states density (N-ss) was obtained from the forward bias I-V data by taking into account voltage dependent effective barrier height (Phi(e)) for two diodes,. i.e. with and without Mo doping. The voltage dependent resistance (R-i) of structures was also obtained using Ohm's law and the method of Nicollian and Brews for the diodes. In order to eliminate the effect of series resistance (R-s), C and G/omega at high frequency values were corrected. N-ss and R-s values were compared between the diodes and experimental results showed that N-ss and R-s values of the Mo-doped PVC+TCNQ structure are considerably lower than those of the undoped PVC+TCNQ structure. The other important parameters such as ideality factor (n), reverse saturation current (I-s), zero-bias barrier heights (Phi(B0)) and R-s were obtained from forward bias I-V data by using I-V, Cheung and Norde methods. Experimental results confirmed that the Mo-doped (PVC+TCNQ) layer considerably improved the performance of the Au/PVC+TCNQ/p-Si structure. (C) 2015 Elsevier Ltd. All rights reserved.

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