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Our study examined how native oxide layers, InN and InSb, affected the current-voltage and capacitance-voltage characteristics of the Au/n-InP Schottky diode at a temperature of 300 K with and without interface states, traps, and tunneling current. The simulation was carried out using the Atlas-Silvaco-Tcad device simulator. From our results, we found that the effective barrier heights were measured to be 0.474 eV, 0.544 eV, and 0.561 eV via I-V measurements and 0.675 eV, 0.817 eV, and 0.80 eV via C-V measurements. Additionally, we utilized the high-low frequency method to calculate the average density of interface state density, which was determined to be approximately 6.03 . 1011 and 3.33 . 1012 сm – 2 . eV – 1. The results indicate that a thin film of InN and InSb can effectively passivate the InP surface, as evidenced by the good performance of the passivized sample. [ABSTRACT FROM AUTHOR]

In this study, three different types of Schottky Barrier diodes were fabricated: Metal-Semiconductor (Au/p-Si) diodes, and pure polyvinyl alcohol (PVA) interface (Au/PVA/p-Si) and 3% Graphene doped PVA interface (Au/PVA:Gr/p-Si) in order to investigate and develop the effect of polymer interface material on the electrical properties of diodes. The electrical properties of the prepared diodes besides the effect of PVA and PVA:Gr interfacial material was investigated. The current-voltage characteristics of each diodes were examined at room temperature. Basic electrical parameters of Au/p-Si, Au/PVA/p-Si, and Au/PVA:Gr/p-Si Schottky Barrier diodes such as series resistance (Rs), barrier height (ΦB0), interface state density (Nss) and ideality factor (n) was obtained from Termionic Emission (TE) theory by using current-voltage data. Norde method was also used to compare the Rs and ΦB0 parameters obtained by the Thermionic Emission theory. The values of n, Rs, and ΦB0 obtained by TE method were found as 14.46, 275.33 Ω, and 0.66 eV for Au/p-Si, 4.98, 155.58 Ω, and 0.72 eV for Au/PVA/p-Si, while it was calculated as 5.61, 432.43 Ω, and 0.77 eV for Au/PVA:Gr/p-Si, respectively. The Rs and ΦB0 values obtained by the Norde method were obtained as 362.39 Ω and 0.70 eV for Au/p-Si, 175.07 Ω and 0.75 eV for Au/PVA/p-Si, while it was found as 525.21 Ω and 0.76 eV for Au/PVA:Gr/p-Si. Values found with Norde and Termionic Emission methods are compatible with each other. Experimental results show that the PVA:Gr interface provides an improvement in the electrical parameters of MPYs. [ABSTRACT FROM AUTHOR]

In this research, the significant role of 1,4,5,8-naphthalenetetracarboxylic-dianhydride, NTCDA, thin film on the Al/p-Si barrier under different temperatures is investigated. The structural and topographical properties of the thermally evaporated NTCDA thin film are investigated using a transmission electron microscope, TEM, and atomic force microscope, AFM, respectively, and elucidated that the fabricated films have a smooth nanocrystalline nature with an average crystallite size about 89 nm and average roughness about 3.15 nm. Furthermore, the current–voltage (I–V) characteristics of Al/NTCDA/p-Si/Al device are studied under dark conditions at different temperatures (313–383 K). The Schottky diode electronic parameters such as ideality factor, n, barrier height, ΦB, and reverse saturation current, Is, are calculated at each temperature. A clear increment of ΦB from 0.74 to 0.88 eV accompanied by a clear decrement of n values from 5.83 to 4.99 under increasing temperature (313–383) K is noticed. Due to the inhomogeneity of barrier height, the Gaussian distribution of Schottky barrier height is employed to estimate the mean value of barrier height and standard deviation and found to be 1.5 eV and 20 mV, respectively. The modified Richardson plot is used to estimate the modified Richardson constant and found to be 35.2 A cm−2 K−2 which is close to the known value of p-Si. Moreover, the conduction mechanism in forward and reverse biasing is explained in details. The modified Norde's function is employed for estimating the series resistance, Rs, and barrier height of the fabricated device at each temperature, where the values of Rs showed a decrement behavior from 3.564 to 1.165 kΩ upon increasing the temperature. The process of inserting NTCDA between electrode and p-Si influenced the distribution of interface states for MIS Schottky diode at different temperatures and is explained as a passivation process of the device's interface states. [ABSTRACT FROM AUTHOR]

The work reveals the design of Au/dysprosium oxide (Dy 2 O 3)/n-GaN metal/insulator/semiconductor (MIS)-type structures with a dysprosium oxide interlayer and investigates its microstructural and chemical states using XRD, TEM and XPS approaches. The outcomes confirm that the Dy 2 O 3 film exists on the n-GaN. The electrical properties of the MIS structure are probed by I–V and C–V procedures. A superior rectifying type with a small leakage current was acquired for the MIS structure rather than the Au/n-GaN Schottky diode (SD). Results showed that the MIS structure has a better barrier height (Φ b) (0.91 eV) than the SD (0.82 eV), representing that the Dy 2 O 3 layer modifies the Φ b. Using Cheung's, Norde and Ψ SP -V plots, the Φ b of the SD and MIS structure are derived and the values are nearly similar, representing that the approaches applied here are valid. The predicted N SS of the MIS structure is two orders smaller than the SD, implying that the Dy 2 O 3 interlayer substantially lowers the N SS. The Poole-Frenkel emission is the foremost current transport at a lower bias, though Schottky emission (SE) is ruled as the current transport at a higher bias of the SD. Nevertheless, the SE is prevailing in the current transport in the MIS structure. Consequences endorse that the Dy 2 O 3 layer can be suitable for building of MIS/MOS devices. [Display omitted] • Structural features of Dy 2 O 3 films were assessed by XRD and TEM. • Electrical properties of Au/n-GaN SD and Au/Dy 2 O 3 /n-GaN MIS structure were explored. • Higher barrier height was achieved for the MIS structure than the SD. • Density of states of the MIS structure was smaller than the SD. • Current conduction process was examined for the SD and MIS structure. [ABSTRACT FROM AUTHOR]

An Au/Ni/β-Ga2O3 Schottky barrier diode was fabricated on an 8.6-μm-thick lightly doped drift region grown on heavily doped Ga2O3 substrate, and its electrical and low-frequency noise characteristics were investigated. The diode showed excellent rectifying behavior with the reverse current being saturated with the applied bias and a magnitude of ∼ 10−13 A. The diode exhibited a barrier height of 1.04 eV and a reasonably high reverse breakdown voltage of 540 V without employing any edge termination methods. The Schottky barrier parameters, such as barrier height, ideality factor, and series resistance, were obtained using a range of methods and found to be in close agreement with each other. The interface state density of the Au/Ni/β-Ga2O3 Schottky diode obtained from the capacitance–voltage (C–V) method was lower than that determined from the forward current–voltage (I–V) characteristics, attributed to the inhomogeneous distribution of interface states at the interface. An analysis of the forward log I–log V plot of the Au/Ni/β-Ga2O3 Schottky diode revealed ohmic-type conduction, and space-charge-limited current dominated the carrier transport mechanisms in lower and higher voltage ranges, respectively. For bias below 0.3 V, the low-frequency noise of the Au/Ni/β-Ga2O3 Schottky diode was a linear combination of two noise components associated with uniformly distributed bulk traps of β-Ga2O3 and the charge fluctuation in the generation-recombination center. On the other hand, for bias above 0.4 eV, the noise spectral density showed a 1/f2 dependence, indicating the domination of generation-recombination noise. [ABSTRACT FROM AUTHOR]

Abstract Radio frequency magnetron sputtered Al-doped zinc oxide (AZO) thin films were formed on n-type gallium nitride (GaN). X-ray diffraction reflections and Raman modes confirmed the formation of the AZO films. The optical band gap of the deposited AZO film was found to be 3.31 eV and exhibited a fairly smooth surface and continuous growth across the surface with a grainy structure. The Au/AZO/n-GaN heterojunction Schottky diode was fabricated and investigated the influence of the presence of AZO layer in Au/n-GaN Schottky diode, characterizing its electrical and breakdown voltage properties. The AZO layer led to an excellent improvement in the rectifying behavior with an increase in barrier height of the Au/n-GaN Schottky diode from 0.69 to 0.90 eV. Reverse breakdown voltage of the Au/n-GaN Schottky diode and Au/AZO/n-GaN heterojunction diode were obtained to be 86 and 232 V, respectively, without any edge termination methods. The AZO layer effectively reduced the interface states in the Au/n-GaN Schottky diodes. Schottky and Poole-Frenkel emission mechanisms dominated the reverse current in Au/n-GaN Schottky diode and Au/AZO/n-GaN heterojunciton diode, respectively. The results signify the importance of the metal-insulator-semiconductor structure and in particular the AZO layer in reducing the leakage current and improving the device performance. A further improvement in breakdown voltage can be achieved by employing field plate and guard-ring structures for edge termination. Highlights • Fabricated Au/Al-doped ZnO (AZO)/n-GaN heterojunction diode by sputtering AZO films. • X-ray diffraction and Raman modes confirmed the formation of AZO films. • AZO films deposited on GaN exhibited a fairly smooth surface with a grainy structure. • Excellent improvement in rectification of Au/n-GaN Schottky diode by AZO insertion. • Breakdown voltage of Au/n-GaN Schottky diode rises from 86 to 232 V by AZO insertion. [ABSTRACT FROM AUTHOR]

Cupric oxide (CuO) is synthesized by simple chemical bath deposition method and deposited on n-type InP substrate using e-beam evaporation technique. First, the structural and chemical compositional analysis of CuO/n-InP are analysed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD and XPS results confirmed that the formation of CuO on n-type InP substrate. Then, Au/CuO/n-InP heterojunction is fabricated with a CuO interlayer and correlated its results with the Au/n-InP Schottky junction (SJ). The barrier height (Φ b ) and ideality factor (n) are extracted through I-V and C-V methods and the respective values are 0.66 eV (I-V)/0.80 eV (C-V) and 1.24, and 0.78 eV (I-V)/0.94 eV (C-V) and 1.62 for the SJ and HJ diodes, respectively. By applying Cheung's and Norde functions, the Φ b , ideality factor and series resistance (R S ) are derived for the SJ and HJ diodes. The derived interface state density (N SS ) of HJ is lower than the SJ; results demonstrated that the CuO interlayer plays an important role in the decreased N SS . The Poole-Frenkel emission is the dominant current conduction mechanism in reverse bias of both SJ and HJ diodes. [ABSTRACT FROM AUTHOR]

Au-CuPc nanocomposite films were prepared by simultaneous evaporation of Au and CuPc with various Au and CuPc concentrations. Microstructural analysis of Au-CuPc films revealed elongated Au cluster formation from isolated Au nanoclusters with increasing Au concentration associated with coalescence of Au clusters. Au-CuPc films with different compositions were employed as interlayer in Al/n-Si Schottky diode. Barrier height and series resistance of the Al/n-Si Schottky diode with Au-CuPc interlayer decreased with increasing Au concentration. This could be associated with the enhancement of electron tunneling between neighboring clusters due to decrease in spacing of Au clusters and formation of conducting paths through the composite material. Interface state density of the Al/n-Si Schottky diode with Au-CuPc interlayer increased with increasing Au concentration. This might be because the inclusion of metal decreases the crystallinity and crystal size of the polymer matrix accompanied by the formation of local defect sites at the places of metal nucleation. [ABSTRACT FROM AUTHOR]

In this work, performance enhancements of a double Schottky rectifier diode with Cu contact on top of p-type Si and a back-side-Al contact due to an optimized thermal annealing process are reported. A decrease of the ideality factor for non-ohmic and ohmic Schottky contacts from 3.17 to 1.15 could be observed in conjunction with a barrier height reduction from 0.59 eV to 0.48 eV by thorough hydrofluoric acid treatment prior to annealing the sample for 15 min. at 450 °C in N 2 atmosphere. Moreover, the barrier height and built-in voltage values decreased by increasing frequency in the ohmic contact structure. The results presented in this work demonstrate such ohmic contacts to be potential candidates for high current and low resistance Schottky diodes and applications. • Fabrication of ohmic and non-ohmic Al back contact/p type Si/Cu Schottky diodes under optimized ambient conditions. • Significant improvements on barrier height values of Schottky barrier diodes with ohmic and non-ohmic Al back contact. • The importance of the ohmic contact application for the ideal metal-semiconductor-metal was determined by ideality factor. • The frequency dependence of the built-in voltage and electron density values for the rectifier diode feature was investigated with C–V-f. [ABSTRACT FROM AUTHOR]

The structural, chemical, electrical and carrier transport properties of high-k ZrO 2 on n-type InP with Au electrode have been studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) , current-voltage (I V) and capacitance-voltage (C V) techniques at room temperature. Results show that the high barrier height is achieved for the Au/ZrO 2 /n-InP metal-insulator-semiconductor (MIS) diode as compared to the Au/n-InP metal-semiconductor (MS) diode. Using Cheung's functions, the barrier height, ideality factor and series resistance are estimated for the MS and MIS diodes. The barrier heights are determined by I V, Cheung's and surface potential-forward voltage plot for both the MS and MIS diodes which are found to be in good agreement with each other. Results indicate that the interface state density of Au/ZrO 2 /n-InP MIS diode is lower than that of Au/n-InP MS diode. This may be attributed to the fact that the introduction of the high-k ZrO 2 interlayer led to reduction of the interface state density in the Au/n-InP MS diode. Results indicate that the Poole-Frenkel emission is the dominant conduction mechanism in the lower bias region while Schottky emission is dominant in the higher bias region for both the Au/n-InP MS and Au/ZrO 2 /n-InP MIS diodes. [ABSTRACT FROM AUTHOR]

This study investigates the effects of annealing on the electrical properties and current transport mechanism of Y/ p-GaN Schottky barrier diodes (SBDs). We found no significant change in the surface morphology of the Y Schottky contacts during the annealing process. The Schottky barrier height (SBH) of the as-deposited Y/ p-GaN SBD was estimated to be 0.95 eV ( I- V)/1.19 eV ( C- V). The SBH increased upon annealing at 400°C and 500°C, and then decreased slightly with annealing at 600°C. Thus the maximum SBH of the Y/ p-GaN SBD was achieved at 500°C, with values of 1.01 eV ( I- V)/1.29 eV ( C- V). In addition, the SBH values were estimated by Cheung's, Norde, and Ψ- V plots and were found to be in good agreement with one another. Series resistance ( R) values were also calculated by I- V, Cheung's, and Norde functions at different annealing temperatures, with results showing a decrease in the interface state density of the SBD with annealing at 500°C, followed by a slight increase upon annealing at 600°C. The forward-bias current transport mechanism of SBD was investigated by the log I-log V plot at different annealing temperatures. Our investigations revealed that the Poole-Frenkel emission mechanism dominated the reverse leakage current in Y/ p-GaN SBD at all annealing temperatures. [ABSTRACT FROM AUTHOR]

Au/Ba 0.6 Sr 0.4 TiO 3 (BST)/n-InP metal/insulator/semiconductor (MIS) Schottky diodes have been analyzed by current-voltage ( I-V ) and capacitance-voltage ( C-V ) measurements. The surface morphology of the BST films on InP is fairly smooth. The Au/BST/n-InP MIS Schottky diode shows better rectification ratio and low leakage current compared to the conventional Au/n-InP metal-semiconductor (MS) Schottky diode. Higher barrier height is achieved for the MIS Schottky diode compared to the MS Schottky diode. The Norde and Cheung's methods are employed to determine the barrier height, ideality factor and series resistance. The interface state density ( N SS ) is determined from the forward bias I-V data for both the MS and MIS Schottky diodes. Results reveal that the N SS of the MIS Schottky diode is lower than that of the MS Schottky diode. The Poole-Frenkel emission is found dominating the reverse current in both Au/n-InP MS and Au/BST/n-InP MIS Schottky diodes, indicating the presence of structural defects and trap levels in the dielectric film. [ABSTRACT FROM AUTHOR]

We report on the effect of oxygen annealing for GaN surface on the Schottky barrier configuration and leakage current in Ni-AlGaN/GaN Schottky barrier diodes. After oxygen annealing, their turn-on voltage and reverse-bias leakage current characteristics are significantly improved due to a reduction in the Schottky barrier height (SBH) and suppression in the surface states respectively. Interface state density extracted from the Terman method was reduced by 2 orders of magnitude. X-ray photoelectron spectroscopy measurements show that the oxygen annealing induces Ga 2 O 3 on the GaN surface. The formation of Ga 2 O 3 reduces the interface state density as well as lowers the SBH through the modification of hybridized metal induced gap states. [ABSTRACT FROM AUTHOR]

The effects of rapid thermal annealing on the electrical and structural properties of a fabricated Au/Y/p-InP Schottky barrier diode (SBD) have been investigated. The estimated Schottky barrier heights (SBHs) of the as-deposited and 200 °C annealed Au/Y/p-InP SBDs are found to be 0.62 eV (I–V)/0.83 eV (C–V) and 0.63 eV (I–V)/0.92 eV (C–V) respectively. However, the SBH increases to 0.65 eV (I–V)/0.96 eV (C–V) upon annealing at 300 °C. Further, the SBH slightly decreases to 0.59 eV (I–V)/0.78 eV (C–V) for contact annealed at 400 °C. The SBH, ideality factor and series resistance of the Au/Y/p-InP SBD are estimated by Norde and Cheung's methods. Also, the discrepancy between SBHs estimated from I–V, C–V, Norde and Cheung's methods are described and discussed. It is noted that the interface state density of the Au/Y/p-InP SBD decreases upon annealing at 300 °C and then slightly increases after annealing at 400 °C. The AES and XRD measurements have revealed that the formation of Au–In, Au–P and Y–P interfacial phases at the interface may be the reason for the increase and decrease of SBHs upon annealing. The AFM results showed that the surface morphology of the Au/Y Schottky contact is fairly smooth at various annealing temperatures. [ABSTRACT FROM AUTHOR]

Electrical properties of Au/n-GaN Schottky rectifier with copper pthalocyanine (CuPc) interlayer were investigated using current–voltage ( I–V ), capacitance–voltage ( C–V ) and conductance–voltage ( G–V ) characteristics. The barrier height obtained for the Au/CuPc/n-GaN Schottky diode was higher than that of the Au/n-GaN Schottky diode. This could be associated with the presence of the CuPc interlayer influencing the space-charge region of the Au/n-GaN structure. The Au/CuPc/n-GaN Schottky structure exhibits higher ideality factor, indicating the higher interface inhomogeneity in Au/CuPc/n-GaN as compared to Au/n-GaN Schottky structure. The density of interface states was extracted using I–V , C–V , and G–V characteristics. The results showed that the introduction of CuPc interlayer facilitated the reduction of interface state density ( N SS ) of Au Schottky contact to n-GaN. Particularly, the N SS obtained from frequency-dependent C–V characteristics was lower than that determined from forward I–V characteristics, which could be attributed to the inhomogeneous distribution of N SS at Schottky interface. [ABSTRACT FROM AUTHOR]

In this paper, 5,6,11,12-tetraphenylnaphthacene (rubrene) was prepared on n type GaAs (100) substrate by spin coating. The device parameters of Al/rubrene/ n -GaAs (100) Schottky diode have been investigated by means of current–voltage ( I–V ) characteristics in the temperature range 100–300 K by steps of 50 K and capacitance–voltage ( C–V ) and conductance–voltage ( G–V ) characteristics at 1 MHz and 300 K. It was observed that ideality factors increased and barrier heights decreased with the decreasing temperature. The observed anomaly of temperature dependence of Schottky barrier height and ideality factor are explained by Gaussian distribution of Schottky barrier height in the same temperature ranges. Al/rubrene/ n -GaAs Schottky barrier diode has been shown to have a Gaussian distribution with mean barrier height ( Φ ¯ B ) of 1.076 eV and standard deviation ( σ s ) of 0.119 V. Schottky barrier height ( Φ B ), series resistance ( R s ), and the density of interface trap states ( N s s ) of the diode were calculated as 1.004 eV, 1.18 k Ω and 2.145 × 10 11 eV −1 cm −2 for 1 MHz, respectively. [ABSTRACT FROM AUTHOR]

Electrical analysis of Al/p-Si Schottky diode with titanium dioxide (TiO) 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/p-Si Schottky diode such as ideality factor ( n), zero bias barrier height ( ϕ) and series resistance ( R) were estimated from forward bias I- V plots. At the same time, values of n, ϕ and R 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/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. [ABSTRACT FROM AUTHOR]

The electrical characteristics of a Pt/n-type Ge Schottky diode with a pyronine-B (PYR-B) interlayer prepared by spin coating was investigated by current–voltage ( I – V ) and capacitance–voltage ( C – V ) measurements. It was observed that the barrier height of Pt/PYR-B/n-type Ge (0.65 eV) was higher than that of the conventional Pt/n-type Ge Schottky diode (0.58 eV). This is attributed to the fact that the organic interlayer increases the effective barrier height by influencing the space-charge region of Ge. The introduction of the PYR-B interlayer led to a reduction of the interface state density in the Pt Schottky contact to n-type Ge. The electric field dependence of the reverse leakage current revealed that Schottky emission and Poole–Frenkel emission mechanisms dominated the reverse current in the Pt/n-type Ge and Pt/PYR-B/n-type Ge Schottky diodes, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The effect of polyvinylidene fluoride (PVDF) polymer interlayer on the rectifying junction parameters of Au/n-InP Schottky diode has been investigated using current–voltage (I–V) and capacitance–voltage (C–V) measurements at room temperature. The calculated barrier heights (BHs) are 0.57eV (I–V), 0.72eV (C–V) and 0.73eV (I–V), 0.88eV (C–V) for the Au/n-InP and Au/PVDF/n-InP Schottky diodes, respectively. Results showed that the BH of the Au/PVDF/n-InP Schottky diode is higher than that of the Au/n-InP Schottky diode, and that the PVDF film increases the effective BH by influencing the space charge region of the n-type InP. The values of the barrier height, ideality factors and series resistance estimated by I–V, Cheung's and Norde methods are compared. Experimental results showed that the interface state density of the Au/PVDF/n-InP Schottky diode is lower than that of the Au/n-InP Schottky diode. Further, the reverse leakage current conduction mechanism is investigated. Schottky emission mechanism is found to dominate the reverse leakage current in the Au/n-InP Schottky diode. However, for the Au/PVDF/n-InP Schottky diode, the Schottky conduction mechanism is found to be dominant in the higher bias region, whereas the Poole–Frenkel conduction is found to be dominant in the lower bias region. Apart from that, the discrepancy between BHs determined from I–V and C–V techniques is explained. Besides, the capacitance–frequency (C–f) and conductance–frequency (G–f) characteristics of the Au/PVDF/n-InP Schottky diode are discussed. [Copyright &y& Elsevier]

Abstract: Using current–voltage (I–V) and capacitance–voltage (C–V) measurements, the effect of oxygen plasma treatment on the electrical properties of Ag Schottky contacts to hydrothermally-grown O-polar bulk ZnO was investigated. Schottky contacts to untreated ZnO had higher barrier heights and lower ideality factors than those to oxygen plasma treated ZnO. The measured C–V and conductance–voltage (G/ω–V) characteristics for both samples showed strong dependences on bias voltage and frequency. The increments of series resistance in small forward bias region (0–0.5 V) was larger for oxygen plasma treated ZnO, indicating that the contribution of interface states to series resistance was more significant. The interface state density was obtained from the corrected C–V and G/ω–V characteristics with considering series resistance. The higher interface state density was found for oxygen plasma treated ZnO, implying that oxygen plasma induced the interface states near the ZnO surface. [Copyright &y& Elsevier]

Highlights: [•] The electrical properties of Au/PVC/n-InP structure have been investigated. [•] The Au/PVC/n-InP Schottky diode exhibits a good rectifying behaviour. [•] A maximum barrier height is achieved after annealing at 100°C. [•] The interface state density is found to be 1.599×1012 eV−1 cm−2 for 100°C annealed contact. [•] Series resistance and interface state density have a significant effect on electrical properties. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cr/n-Si Schottky Schottky barrier diodes were prepared by the electrodepositing method. [•] The electrical characteristics of the Cr/n-Si Schottky barrier diode were investigated. [•] The interface state density of the diode has an exponential rise. [•] The main parameters were calculated using different methods. [Copyright &y& Elsevier]

A thin poly(ethylmethacrylate) (PEMA) layer is deposited on n-InP as an interlayer for electronic modification of Au/n-InP Schottky structure. The electrical properties of Au/PEMA/n-InP Schottky diode have been investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements at different annealing temperatures. Experimental results show that Au/PEMA/n-InP structure exhibit a good rectifying behavior. An effective barrier height as high as 0.83 eV (I–V) and 1.09 eV (C–V) is achieved for the Au/PEMA/n-InP Schottky structure after annealing at 150 °C compared to the as-deposited and annealed at 100 and 200 °C. Modified Norde's functions and Cheung method are also employed to calculate the barrier height, series resistance and ideality factors. Results show that the barrier height increases upon annealing at 150 °C and then slightly decreases after annealing at 200 °C. The PEMA layer increases the effective barrier height of the structure as this layer creates a physical barrier between the Au metal and the n-InP. Terman's method is used to determine the interface state density and it is found to be 5.141 × 1012 and 4.660 × 1012 cm−2 eV−1 for the as-deposited and 200 °C annealed Au/PEMA/n-InP Schottky diodes. Finally, it is observed that the Schottky diode parameters change with increasing annealing temperature. [ABSTRACT FROM AUTHOR]

Highlights: [•] C–f and G–f characteristics of Ir/n-InGaN SBDs are studied at different temperatures. [•] The N ss and τ of the Ir/n-InGaN SBD are determined from C–f characteristics. [•] N ss show a decrease with bias from the bottom of the CB towards the mid gap at various temperatures. [•] Results reveal that the values of relaxation time τ are higher towards the low temperature. [ABSTRACT FROM AUTHOR]

Abstract: We have investigated the current transport mechanisms in Ru/Pd/n-GaN Schottky barrier diodes in the temperature range 105–405K. The calculated barrier height and ideality factor are 0.27eV and 3.93 at 105K, and 0.75eV and 1.29 at 405K respectively, and it is observed that barrier height (Φbo) decreases and the ideality factor (n) increases with decreasing temperature. The apparent barrier height and the ideality factor derived by using thermionic emission theory are found to be strongly temperature dependent. This behavior has been interpreted based on the assumption of a Gaussian distribution of barrier heights due to barrier height inhomogeneities that prevail at the metal–semiconductor interface. The linearity of the apparent barrier height versus 1/2kT plot yields a mean barrier height () of 0.89eV and a standard deviation (σ o) of 111mV. A modified versus 1000/T plot gives (T =0) and A ∗ as 0.87eV and 21.25A/cm2 K2, respectively without using the temperature coefficient of the barrier heights. The interface state densities extracted for the Ru/Pd/n-GaN Schottky diode are in the range of 9.38×1013 to 1.06×1012 eV−1 cm−2 in the band gap below conduction band from E C-0.14 to E C-0.66eV. Deep level transient spectroscopy (DLTS) results showed that the two deep level defects are observed in as-grown sample (E 1 and E 2) which have activation energies of E 1 =0.54eV and E 2 =0.68eV, suggest that E 2 level is most probably associated with N Ga-related defect. [Copyright &y& Elsevier]

Abstract: In the present work, we have investigated the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of Au/SiO2/n-GaN metal–insulator–semiconductor (MIS) Schottky diode and compared with Au/n-GaN metal–semiconductor (MS) Schottky diode. Calculations showed that the Schottky barrier height and ideality factor of the MS Schottky diode is 0.79eV (I–V), 0.87eV (C–V) and 1.45, respectively. It is observed that the Schottky barrier height increases to 0.86eV (I–V), 0.99eV (C–V) and ideality factor deceases to 1.3 for MIS diode. For the MS diode, the calculated doping concentration is 4.17×1017 cm−3. However, in the case of the MIS Schottky diode, the decrease in doping concentration is observed and the respective value is 2.08×1017 cm−3. The obtained carrier concentration of the MIS diode is reduced about 50% when compared to the MS diode. The interface state density as determined by Terman''s method is found to be 3.79×1012 and 3.41×1010 cm−2 eV−1 for the MS and MIS Schottky diodes, respectively. The calculated interface densities are 2.47×1011 cm−2 eV−1, 3.35×1011 cm−2 eV−1 and 3.5×1011 cm−2 eV−1 for the sweep rates of 300, 450 and 600mV/s from MOS C–V measurements for the MIS Schottky diode. The interface state density calculated from Terman''s method is found to be increased with sweep rate. From the C–V measurement, it is noted that the decrease in the carrier concentration in MIS diodes as compared to MS diode may be due to the presence of oxide interfacial layer. DLTS measurements have also been performed on MIS Schottky diode and discussed. [Copyright &y& Elsevier]

Metal-insulator-semiconductor Schottky diodes were fabricated to investigate the tunnel effect and the dominant carrier transport mechanism by using current density-voltage (J-V) and capacitance-voltage (C-V) measurements in the temperature range of 295-370 K. The slope of the ln J-V curves was almost constant value over the nearly four decades of current and the forward bias current density J is found to be proportional to Jo (T) exp(AV). The values of Nss estimated from J-V and C-V measurements decreased with increasing temperature. The temperature dependence of the barrier heights obtained from forward bias J-V was found to be entirely different than that from the reverse bias C-V characteristics. All these behaviours confirmed that the prepared samples have a tunnel effect and the current transport mechanism in the temperature range of 295-370 K was predominated by a trap-assisted multi-step tunnelling, although the Si wafer has low doping concentration and the measurements were made at moderate temperature. [ABSTRACT FROM AUTHOR]

Abstract: Thin film of poly(3-octylthiophene) (P3OT) was successfully prepared using dip coating technique. The morphology and the crystal structure of the prepared thin film were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. A study on interface states density distribution and characteristic parameters of the Al/P3OT/ITO device capacitor have been made. The diode parameters such as ideality factor, series resistance and barrier height were extracted from the forward biasing J–V characteristics. The energy distribution of the interface state density D it was determined from the forward bias J–V characteristics by taking into account the bias dependence of the effective barrier height. The C–V and G/ω–V characteristics were measured in the frequency range from 10kHz to 1MHz and dc biasing voltage swept from −4V to +4V at room temperature (300K). The non-ideal behavior of J–V and C–V characteristics can be attributed to the presence of the interface and the series resistance. [Copyright &y& Elsevier]

Abstract: We have fabricated a poly(aniline-3-methyl thiophene) organic thin material on p-Si substrate by placing a solution of copolymer in acetonitrile on top of a p-Si substrate and then evaporating the solvent. The electrical and interface state density properties of the poly(aniline-3-methyl thiophene) copolymer/p-Si/Al diode have been investigated through methods using current–voltage (I – V), Cheung''s, and a modified Norde''s function. Good agreement was observed with the values of barrier height as obtained from all of these methods. The diode shows a non-ideal I – V behavior with an ideality factor greater than unity, which could be ascribed to the interfacial layer, interface states and series resistance. The interface state density of diode was determined using the forward-bias I – V characteristic technique at room temperature, and it decreases exponentially with bias from 1.39×1016 cm− 2 eV− 1 in (0.06− E v) eV to 4.86×1015 cm− 2 eV− 1 in (0.51− E v) eV. [Copyright &y& Elsevier]

Abstract: We have formed conjugated polymeric aniline–thiophene organic material on p-Si substrate by adding polyaniline–poly-3-methyl thiophene blend solution in acetonitrile on top of a p-Si substrate and then evaporating the solvent. It has been seen that the forward bias current–voltage (I–V) characteristics of polyaniline–poly-3-methyl thiophene blend/p-Si/Al with a barrier height value of 0.60eV and an ideality factor value of 3.37 showed rectifying behaviour at room temperature. The polyaniline–poly-3-methyl thiophene blend/p-Si/Al Schottky barrier diode showed non-ideal I–V behaviour with the value of ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. Furthermore, Cheung''s functions and modified Norde''s function were used to extract the diode parameters including ideality factor, barrier height and series resistance. It has been seen that there is a good agreement between the barrier height values from all methods. However, the values of series resistance obtained from Cheung''s functions is higher than the values obtained from Norde''s functions. The energy distribution of interface states density, determined from forward bias current–voltage (I–V) characteristic technique at room temperature, increases exponentially with bias from 2.81×1016 cm−2 eV−1 in (0.73–E v) eV to 1.14×1017 cm−2 eV−1 in (0.48–E v) eV. [Copyright &y& Elsevier]

Abstract: The electrical characterization of the In/p-Si Schottky diode has been investigated by conductance and capacitance–frequency techniques. The characteristic parameters of the interface states have been determined from the capacitance–frequency and conductance–frequency measurements. The capacitance of the In/p-Si Schottky diode decreases with increasing frequency. The increase in capacitance at lower frequencies results from the presence of interface states. The peak observed in the conductance curve of the In/p-Si diode indicates the presence of an interfacial layer in the In/p-Si Schottky barrier. The interface-state parameters, interface-state density D it and relaxation time τ of the In/p-Si diode were calculated. The interface-state density was found to vary from 7.82×1012 eV−1 cm−2 in (0.53−E v)eV to 8.01×1012 eV−1 cm−2 in (0.28−E v)eV. Furthermore, the relaxation time was found to vary from 4.543×10−8 s in (0.53−E v)eV to 4.435×10−8 s in (0.28−E v)eV. [Copyright &y& Elsevier]

Abstract: Schottky diodes with good rectifying characteristics have been fabricated on the polycrystalline silicon–germanium (poly-Si1− x Ge x ) thin film, deposited by the ion-beam-sputtering (IBS) technique. The influence of the Ge mole fraction and annealing condition on the electrical characteristics of a NiSi-Schottky diode grown on poly-Si1− x Ge x film has been studied. NiSi-Schottky diodes are characterized in the temperature range of 125–300 K for the determination of Schottky barrier height (SBH), ideality factor (n), and interface–surface–grain-boundary state density (D it). The current–voltage (I–V) characteristics have also been simulated in SEMICAD device simulator, by incorporating a modified poly-grain growth and mobility model of poly-SiGe material system to predict the effect of annealing temperature on the electrical properties of poly-Si1− x Ge x Schottky diode. [Copyright &y& Elsevier]

Abstract: Electronic and interface state distribution properties of Ag/p-Si Schottky diode have been investigated. The diode indicates non-ideal current–voltage behavior with an ideality factor greater than unity. The capacitance–voltage (C–V) characteristic is linear in reverse bias indicating rectification behavior and charge density within depletion layer is uniform. From I–V and C–V characteristics, junction parameters such as diode ideality factor and barrier height were found as 1.66 and ϕ B(I–V) =0.84eV (ϕ B(C–V) =0.90eV), respectively. The interface state density N ss and relaxation time τ of the Schottky diode were determined by means of Schottky capacitance spectroscopy method. The results show the presence of thin interfacial layer between the metal and semiconductor. [Copyright &y& Elsevier]

This paper reviews the microstructural and electrical properties of Au/n-GaN metal/semiconductor (MS) diode with an e-beam evaporated SrTiO 3 (STO) as an insulating layer between the Au and n-GaN substrate. The microstructural properties of STO thin films are assessed by employing XRD and TEM approaches and the results reveal that the STO thin films are formed on n-GaN surface. Then, the Au/STO/n-GaN heterojunction (HJ) type Schottky diode is fabricated and measured its electrical characteristics by current-voltage (I–V) and capacitance-voltage (C–V) techniques. The HJ exhibits lower reverse leakage current compared to the MS diode. Higher barrier height is achieved for the HJ (0.86 eV) than the MS diode (0.67 eV) with ideality factors of 1.86 and 1.21. This implies that the barrier height is modified by the STO insulating layer. Using Z(V,T) i - V d and Ψ S -V plots, the barrier heights of MS diode and HJ are also evaluated and compared with one another. The derived interface state density (N SS) of HJ is lower than the MS diode, demonstrating that the STO layer plays a substantial role in the reduced N SS. Results suggest that the STO thin film is a promising high-k material for the development of new electronic device applications. Image 1 • Microstructural properties of SrTiO 3 films are characterized by XRD and TEM. • Electrical properties of Au/n-GaN MS diode and Au/SrTiO 3 /n-GaN HJ have been studied. • Higher BH is obtained for the HJ than the MS diode. • Interface state density of HJ is lower as compared to the MS diode. [ABSTRACT FROM AUTHOR]

This study examined the temperature-dependent current-voltage (I–V) characteristics of the Ni/Au Schottky contact to β -Ga 2 O 3. The Au/Ni/ β -Ga 2 O 3 Schottky diode showed a good rectifying behavior. The on-resistance and rectification ratio decreased with increasing temperature, which could be ascribed to the increase in the number of thermally activated electrons. The Au/Ni/ β -Ga 2 O 3 Schottky diode exhibited the strong temperature-dependence of Schottky barrier parameters, indicating the presence of inhomogeneous Schottky barrier prevailing in the interface between Ni and β -Ga 2 O 3. The inhomogeneities were analyzed using thermionic emission with assuming a Gaussian distribution of barrier heights. The results revealed the existence of a double Gaussian distribution of barrier heights in the diode with a transition occurring at 225 K. The modified Richardson plot was evaluated using a Gaussian distribution approach and yielded a Richardson constant closely matching with the theoretical value of β -Ga 2 O 3. The density of interface states, extracted using I–V characteristics, increased with decreasing temperature, which could be associated with the thermally-driven restructuring and reordering of the Ni/ β -Ga 2 O 3 interface state. • Schottky barrier parameters of the Au/Ni/ β -Ga 2 O 3 Schottky diode were evaluated using I – V – T characteristics. • Decline in on-resistance and rectification ratio at high temperature could be due to rise of thermally activated electrons. • Temperature dependency of Schottky barrier parameters of Au/Ni/ β -Ga 2 O 3 Schottky diode was due to barrier inhomogeneities. • Au/Ni/ β -Ga 2 O 3 Schottky diode showed double Gaussian distribution of barrier height with a mean value for each distribution. [ABSTRACT FROM AUTHOR]