Type Schottky Barrier Diodes Research Articles

The investigation of current-transport mechanisms (CTMs) in the Al/(In2S3:PVA)/p-Si (MPS)-type Schottky barrier diodes (SBDs) at low and intermediate temperatures

The investigation of current-transport mechanisms (CTMs) in the Al/(In2S3:PVA)/p-Si (MPS)-type Schottky barrier diodes (SBDs) at low and intermediate temperatures

A Study on the Wide Frequency Range Electrical Variables in the Al/Coumarin–PVA/p-Si Diodes at Room Temperature

Coumarin-PVA is deposited onto p-Si wafers using the spin coating technique. I examined the fundamental electrical variables of the Al/CoumarinPVA/p-Si type Schottky barrier diodes (SBDs), by utilizing capacitance/voltage(C-V) and conductance/voltage (G-V) measurements at different frequencies varied from 10kHz to1MHz. I have thoroughly explored how the CoumarinPVA interlayer, series resistance (Rs) and surface states (Nss) affect the electrical properties of SBDs. In order to remove Rs's influence on the observed C and G values, I corrected them. The observed high values of C/G measured at low frequencies result from the existence of interfacial states. There is evidence that while NA decreases exponentially with increasing frequency, B increases exponentially. A particular distribution of Nss density, polarization processes, and the existence of an interfacial layer can all contribute to explaining these characteristic features of them. According to experimental findings, I conclude that the interfacial polymer CoumarinPVA layer as well as the Nss and Rs also have a significant impact on the C/G-V quantities of SBDs.

Fabrication of Cu/Y-MoO3/p-Si type Schottky barrier diodes by facile spray pyrolysis technique for photodetection application

The metal-semiconductor interface is a regular multitudinous photoelectric device like Schottky barrier diodes (SBDs) applications. Here we have designed a metal-insulator-semiconductor (MIS) photo detector primarily based on Y-MoO3 film fabricated on p-type Si substrate. The Y-MoO3 film is coated with different Y (5, 10 and 15 wt%) concentrations using the jet nebuliser spray paralysis (JNSP) technique with a glass substrate of a target at 500 °C. XRD pattern of Y-MoO3 film with 15 wt% revealed monoclinic structure with good crystalline nature and improved grain size. FE-SEM photographs of the higher concentrated film exhibited agglomerate nanoplate structures, and the EDAX spectrum confirmed the stoichiometric ratio of O, Mo and Y elements. The UV absorption spectrum displayed comprehensive bandgap energy for a higher concentration of Y (15 wt%). The conductivity (σ) decreased for higher concentration Y-MoO3 thin films elevated values of corresponding activation energy and resistivity. The fabricated Cu/Y-MoO3/p-Si type SBDs have good rectification behaviour of all the diodes, specifically for 15 wt% of Y. The photodiode behaviours of various parameters such as (n) with corresponding (ΦB), (PS), (R), (QE) and (D*) were calculated for light intensities based on the I-V characteristic.

Enhanced Electrical Performance of in Doped LaPO4 as an Interfacial Layer of Cu/In-LaPO4/n-Si Structured Type Schottky Barrier Diode

Enhanced Electrical Performance of in Doped LaPO4 as an Interfacial Layer of Cu/In-LaPO4/n-Si Structured Type Schottky Barrier Diode

A Study on Annealing Process Influenced Electrical Properties of Ni/CeO2/p‐Si/Al Schottky Barrier Diodes

AbstractThe impact of annealing process on I‐V characteristics of Ni/CeO2/p‐Si/Al metal‐insulator‐semiconductor (MIS) type Schottky barrier diodes is investigated. The I‐V measurements are performed for the as‐deposited and 700 °C annealed samples at room temperature. The Schottky barrier height (SBH), ideality factor values are evaluated using thermionic emission theory and are found to be 0.67 eV, 1.21 for the as‐deposited sample and 0.72 eV, 1.01 for the 700 °C annealed sample. The calculations indicate that the 700 °C annealed sample for 45 min exhibits a lower series resistance (680 Ω) when compared to the as‐deposited sample (2206 Ω). The calculated shunt resistance for the 700 °C annealed sample is found to be 346 × 103 Ω which is found to be lower than that of the as‐deposited sample that is 962 × 103 Ω. In conclusion, it is elucidated that the intentionally deposited CeO2 (rare‐earth oxide) insulating layer at the interface of Ni/p‐Si and the subsequent annealing process significantly influence the electrical properties of the fabricated Ni/CeO2/p‐Si/Al MIS type Schottky barrier diodes.

Voltage Dependent Barrier Height, Ideality Factor and Surface States in Au/(NiS-PVP)/n-Si (MPS) type Schottky Barrier Diodes

Metal-Polymer-Semiconductor (MPS) Schottky Barrier Diodes (SBD) were manufactured and their basic electrical parameters were obtained by the measurement of the forward and reverse bias current-voltage (I-V) in the wide bias voltage range (±3V) to determine the voltage dependent effects on Nickel-Sulphur (NiS) doped Poly Vinyl Pyrrolidone (PVP) polymer interlayer. The saturation current (I0), zero-bias barrier height (ΦB0), rectifying rate (RR), ideality factor (n) and the real value of series - shunt resistances (Rs - Rsh) were calculated. The voltage dependent profile of n (V), ΦB(V), and Rs (V) were derived. The forward bias ln I-V plot of the MPS type SBD indicates a good rectifier behaviour and it has two distinctive linear parts with different slopes which correspond to low (0.288 ≤V ≤0.625 V) and moderate (0.672 ≤ V ≤ 0.960 V) bias voltages and then deviates from linearity due to Rs and interlayer at high forward bias voltages. Energy dependent profile of Nss was obtained from the forward bias I-V data by considering voltage dependent barrier height (ΦB) and n. Nss plot represents U-shape behaviour in the forbidden bandgap. The mean value of Nss was found at about 7.0x1012 eV-1 cm-2 and this value is in the acceptable limit for a semiconductor device and such lower values of Nss are the consequences of the passivation effect on the surface states.

Upgraded photosensitivity under the influence of Yb doped on V2O5 thin films as an interfacial layer in MIS type Schottky barrier diode as photodiode application

In this study, rare earth ytterbium (Yb)-doped V2O5 thin films were effectively coated on glass and Si substrates by the sol-gel method combined with the spin coating method. The films' structural, morphological, optical, and electrical properties were investigated through XRD, FESEM, UV-Vis, and I-V electrical conductivity. Doping on V2O5 with low Yb content of 2, 4, and 6 ​wt % have highly affected the lattice, which is shown in tetragonal and orthorhombic structures. Morphological studies show nanorods like structured. The coated thin films yield bandgap of 3.23–3.31 ​eV. The electrical properties of Cu/Yb@V2O5/n-Si type Schottky barrier diode were studied, and calculated photodiode parameters like photosensitivity, photo-responsivity, external quantum efficiency, and detectivity. Predominantly, high photosensitivity of 5545.70% is obtained for the diode with 2 ​wt % Yb@V2O5.

The reverse bias current–voltage–temperature (I–V–T) characteristics of the (Au/Ti)/Al2O3/n-GaAs Schottky barrier diodes (SBDs) in temperature range of 80–380 K

We analyzed current conduction mechanisms (CCMs) of the (Au/Ti)/Al2O3/n-GaAs (MIS) type SBDs in the wide temperature range (80–380 K) by 30 K steps using reverse bias current-voltage (IR–VR) characteristics. In general, the values of barrier-height (BH) obtained from the forward bias current–voltage (IF–VF) and reverse bias current-voltage (IR–VR) characteristics increase with increasing temperature and this change is in-agreement with the reported negative-temperature coefficient bandgap of semiconductor (α = ΔEg/ΔT) or BH for ideal SDs. However, the change in BH at lower temperatures becomes more pronounced. The value of BH obtained from the IR–VR data is lower than that obtained from IF–VF especially under room temperatures. The necessary barrier height (Φt) for electron emission from the trap state was obtained from the ln (IR) − E0.5, (E = VR/d), plot as 1.25 eV to (at 80 K) 0.91 eV (at 380 K), respectively. This change in the Φt with temperature is in agreement with the reported α value of the Eg for GaAs. The reverse leakage current mechanism in this study was assessd for various temperatures using Schottky emission (SE), Poole–Frenkel emission (PFE), Trap-Assisted Tunneling (TAT), and ohmic conduction mechanisms. The evaluation of the IR–VR characteristics shows that the ohmic and TAT are the most dominant conduction mechanisms rather than others.

Investigation on UV Photoresponsivity of main electrical properties of Au/CuO-PVA/n-Si MPS type Schottky Barrier Diodes (SBDs)

In this study, (CuO doped PVA) composite material was deposited using spin coating technique on n-Si and the Au/CuO-PVA/n-Si Metal/Polymer/Semiconductor type Schottky Barrier Diodes (MPS type SBDs) were fabricated. The electrical measurements of Au/CuO-PVA/n-Si SBDs were realized in the dark and under various UV (365 nm) light intensities ranging from 50 to 250 mW/cm2. The basic parameters of the MPS type SBDs such as leakage current (I0), zero bias barrier height (ΦB0), barrier height (ΦB), ideality factor (n), series resistance (Rs), shunt resistance (Rsh), rectification rate (RR), photocurrent (Ipc) and surface states (Nss) were obtained Current-Voltage (I–V) plot based on Thermionic Emission (TE) theory, and Norde function depending on the UV light intensity. As the light intensity increases, RR, Rsh, ΦB0, and ΦB decreased but the n and I0 increased. In addition, the increase of UV light intensity caused the increase of photocurrent in MPS type SBDs and thus MPS type SBDs exhibited more ohmic behavior.

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In this study, (CuO doped PVA) composite material was deposited using spin coating technique on n-Si and the Au/CuO-PVA/n-Si Metal/Polymer/Semiconductor type Schottky Barrier Diodes (MPS type SBDs) were fabricated. The electrical measurements of Au/CuO-PVA/n-Si SBDs were realized in the dark and under various UV (365 nm) light intensities ranging from 50 to 250 mW/cm2. The basic parameters of the MPS type SBDs such as leakage current (I0), zero bias barrier height (ΦB0), barrier height (ΦB), ideality factor (n), series resistance (Rs), shunt resistance (Rsh), rectification rate (RR), photocurrent (Ipc) and surface states (Nss) were obtained Current-Voltage (I–V) plot based on Thermionic Emission (TE) theory, and Norde function depending on the UV light intensity. As the light intensity increases, RR, Rsh, ΦB0, and ΦB decreased but the n and I0 increased. In addition, the increase of UV light intensity caused the increase of photocurrent in MPS type SBDs and thus MPS type SBDs exhibited more ohmic behavior.

Investigation of the electrical properties of diodes by crosschecking dependence on the presence of (nanocarbon-PVP) interface layer

The Al/p-Si (metal-semiconductor (MS)) and Al/nanocarbon-PVP/p-Si (metal-polymer-semiconductor) type Schottky barrier diodes (SBDs) were fabricated in same conditions to determine the existence of an increase in the performance of Al/p-Si diode and they were called as D1 and D2, respectively. For this purpose, the electrical properties of the diodes were investigated using the current–voltage and impedance–voltage measurements in wide bias voltage. The ideality factor, reverse-saturation current and zero-bias barrier height values were calculated from the linear part of the forward bias lnI–V plot as 6.23, 2.35 ✕ 10–8A, 0.68 eV for D1 and 2.86, 4.27 ✕ 10–9A, 0.73 eV for D2, respectively. It is seen from results that the value of rectifier rate for D2 is about 8 times higher than for D1. The values of barrier height, Fermi energy level, the number of doped acceptor atoms and depletion layer width were obtained. The values of series resistance and special density distribution of interface states’ values also considerably decrease using (nanocarbon Polyvinylpyrrolidone (PVP)) interlayer. All these results confirmed that the nanocarbon-PVP polymer interlayer leads to a seriously increase in the performance of the MS diodes and hence it can be successfully used as an insulator in view of low cost, grown by simple methods.

Determination of Structural Properties of Some Important Polymers Used as Interfacial Layer in Fabrication of Schottky Barrier Diodes (SBDs)

In this study, structural, electronic and thermal properties of important polymers such as Perylene (PER), Polypyrrole (PPy) and Polyvinyl alcohol (PVA) commonly used in the production of metal-polymer-semiconductor (MPS) type Schottky Barrier Diodes (SBDs) were determined. Since the opto-electronic properties of the materials depend on the electronic band gap, the High Occupied Molecular Orbital (HOMO) and Low Unoccupied Molecular Orbital (LUMO) energies for the polymeric structures and the gap between of energy levels were calculated. In addition, entropy, heat capacity and total thermal energy values were calculated over a wide temperature range and it was determined how thermochemical properties of polymers were affected with temperature. The obtained results showed that while PER has a planar structure, PPy and PVA has a non-planar structure. PER also has the highest chemical reactivity among the polymers examined with large band gap calculated as 3.03 eV. In addition, thermochemical parameters of all polymers increase with increasing temperature almost as linearly.

Fabrication and characterization of rare earth (Ce, Gd, and Y) doped ZrO2 based metal-insulator-semiconductor (MIS) type Schottky barrier diodes

The 8 wt% rare earth (RE = Ce, Gd, and Y) doped zirconium dioxide (ZrO2) thin films were prepared on glass substrates by spin-coating technique and annealed at 600 °C. Also, the RE:ZrO2 based metal-insulator-semiconductor (MIS) type Schottky barrier diodes were fabricated. X-ray diffraction (XRD) patterns revealed the mixed phase of monoclinic and tetragonal ZrO2 for the RE:ZrO2 films, and the pure monoclinic phase for the undoped ZrO2 film. Because of the doping with RE ions, the crystallite size reduced with the increase of oxygen vacancies. The scanning electron microscopic (SEM) images exhibited the rod-shaped and square-shaped grains for the undoped ZrO2 and Gd:ZrO2 thin films, respectively. Elemental compositions were confirmed by the energy dispersive X-ray (EDX) analysis. The UV–vis analysis showed the lower transmittance for the RE:ZrO2 films with a reduced band gap (Eg). The dc electrical conductivity (σdc) was increased with the decrease of activation energy (Ea) due to the RE doping. When compared to the Al/undoped ZrO2/p-Si Schottky barrier diode, the Al/RE:ZrO2/p-Si showed an improvement in the values of barrier height (ΦB), ideality factor (n), and series resistance (RS).

Effect of Organic Additives on the Characteristics of Al/Organic Additive:ZrO2/p-Si Metal–Insulator-Semiconductor (MIS) Type Schottky Barrier Diodes

In this work, zirconium dioxide (ZrO2) thin films were prepared on glass substrates with organic additives such as polyethylene glycol-6000 (PEG), polysorbate-80 (P80), triton X-100 (T100), citric acid (CA), tartaric acid (TA), and oxalic acid (OA) by sol–gel spin coating technique. The prepared thin films were annealed at 600 °C and their structural, morphological, optical and dc electrical properties were studied. From the XRD pattern, the crystal structure of the ZrO2 films was found to be monoclinic. The SEM micrographs of PEG:ZrO2 and CA:ZrO2 thin films exhibited rod-shaped and square-shaped grains, respectively. The EDX analysis confirmed the presence of Zr and O elements in the ZrO2 films. The UV–Vis analysis showed a higher transmittance for the PEG:ZrO2 and T100:ZrO2 films. The optical band gap (Eg) varied in the range of 5.66–5.83 eV. DC electrical conductivity (σdc) increased with a decrease of activation energy (Ea) for organic additive:ZrO2 thin films compared to pure ZrO2. A maximum value of σdc was noticed for the PEG:ZrO2 thin film. Metal–insulator-semiconductor type Schottky barrier diodes (Al/organic additive:ZrO2/p-Si) were fabricated and their electrical characteristics were studied. Results showed that the barrier height (ΦB), series resistance (Rs) and ideality factor (n) decreases for Al/organic additive:ZrO2/p-Si SBDs from that of the Al/Pure ZrO2/p-Si.

Electrical characteristics analyses of zinc-oxide based MIS structure grown by atomic layer deposition

The ZnO films are grown on the p-type Si for metal-insulator-semiconductor (MIS) type Schottky barrier diode (SBHS) fabrication by atomic layer deposition (ALD) method. The electrical characteristics of the three diodes called as D1, D2 and D3 have been investigated. The surface characteristics and thin film in structure were detected by secondary ion mass spectrometry (SIMS) and atomic force microscopy (AFM). The current-voltage (I–V) properties of Al/ZnO/p-Si structures were analyzed in the dark at room temperature. The electrical specifications such as, barrier height (ϕb) ideality factor (n) and series resistance (Rs) of these structures were examined by Norde’s function, Cheung method and thermionic emission (TE) theory. Barrier height values computed from Cheung and I–V method was found to be different from each other. Interface state density (Dit) of these structures was studied using the I–V properties. The non-ideal behavior of measured characteristics advised the presence of interface conditions. The acquired results imply that the fabricated diodes can be used for NIR Schottky photo detector applications.

Investigation of temperature dependent negative capacitance in the forward bias C-V characteristics of (Au/Ti)/Al2O3/n-GaAs Schottky barrier diodes (SBDs)

In this study, a metal-insulator-semiconductor (MIS) type Schottky barrier diodes (SBDs) were fabricated by growing a thin Al2O3 insulator layer between Au/Ti and n-GaAs using atomic layer deposition (ALD) method. The effect of temperature and voltage on interface states (Nss) and series resistance (Rs) of the (Au/Ti)/Al2O3/n-GaAs (MIS) type Schottky barrier diodes (SBDs) was investigated using the capacitance/conductance-voltage (C/(G/ω)-V) data measured in wide range of temperature (200–380 K) and voltage ( ± 5 V). It was found that C and G/ω are strongly dependent on temperature and voltage. The value of C in the forward bias region reaches to maximum and then becomes negative. This negative capacitance (NC) behavior of this SBD is observed for each temperature level. Also, capacitance-current (C-I) and conductance-current (G/ω-I) plots were drawn to explain the NC behavior. The negative value of C in the accumulation region corresponds to the maximum value of G/ω. Such behavior of C can be explained by the loss of interface charges located at (Al2O3)/n-GaAs interface because of impact ionization process, the existence of surface states (Nss), series resistance (Rs) and interfacial of (Al2O3) oxide layer.Therefore, the voltage dependent profiles of Rs and Nss were obtained using Nicollian-Brews and Hill-Colleman methods for enough high forward biases as a function of temperature at various positive bias voltages. The changes in Rs and Nss values were attributed to restructure and reordering of the carriers under temperature and voltage effects.

Electrical Characterizations of ZnO-Based MOS-Type Schottky Barrier Diodes

The electrical properties of Al/ZnO/p-Si MOS (metal-oxide semiconductor)-type Schottky barrier diodes have been investigated in this study. ZnO layer on p-type Si (111) substrate was deposited by evaporation technique. The two contacts were constructed as one top and one bottom contacts. Al rectifying contacts was formed on the top of ZnO layer. Al ohmic contact was formed the back surface of the Si wafer. The current-voltage (I-V) characteristics of Al/ZnO/p-Si diodes were measured at room temperature and in the dark. The main electrical parameters of Al/ZnO/p-Si MOS-type structures, such as the ideality factor (n), barrier height ( ) and series resistance (Rs) have been analyzed and calculated from current-voltage (I-V) characteristics by using thermionic emission theory and Cheung method

On the conduction mechanisms of Au/(Cu2O–CuO–PVA)/n-Si (MPS) Schottky barrier diodes (SBDs) using current–voltage–temperature (I–V–T) characteristics

The temperature effect on the conduction mechanism of Au/Cu2O–CuO–PVA/n-Si (MPS) type Schottky barrier diodes (SBDs) have been investigated in detail in the wide temperature range of 100–380 K by using the forward bias current–voltage (I–V) measurements. It is observed that the semi logarithmic forward bias I–V plots have two distinct linear regions with different slopes for each temperature. These regions are called low bias region (LBR) and moderate bias region (MBR), respectively. The LBR and MBR correspond to (0.6–1.04 V) and (1.10–1.65 V) bias voltages, respectively. Main diode parameters such as reverse saturation current (I0), ideality factor (n) and zero-bias barrier height (Φb0) were calculated for these two regions. It is observed that the values of Φb0 increased as the values of n decreased with the increasing temperature and such behavior of Φb0 and n with temperature was attributed to the barrier inhomogeneities by assuming Gaussian distribution (GD) at the M/S interface. The Φb0 versus n and q/2kT plots were drawn to get an evidence of the GD. These two plots also have two linear regions at LBR and MBR. These regions are called the low temperature region (LTR) and high temperature region (HTR). Thus the mean values of barrier height (BH) and standard deviation (σs) were obtained by using the intercept and slope of these plots. After that, the conventional Richardson plot was drawn [(Ln(I0/T2) − q2σs 2/2k2T2) vs. q/kT] and it also has two linear regions. The main values of BH and effective Richardson constant (A*) were obtained from the slope and intercept of these plots. These values are found as 0.82 eV and 110.7 A/cm2 K2 for LTR and 1.53 eV and 115.5 A/cm2 K2 for HTR in the LBR and 0.77 eV and 111.9 A/cm2 K2 for LTR and 1.26 eV and 133.9 A/cm2 K2 for HTR in the MBR, respectively. The obtained values of A* are in good agreement with their theoretic values (112 A/cm2 K2) especially for HTR. Thus, the I–V–T characteristics of MPS type SBDs are successfully explained by the double GD model. Besides, the interface state density (Nss) of the MPS diode was calculated from forward-bias I–V measurements.

Investigation of the C-V characteristics that provides linearity in a large reverse bias region and the effects of series resistance, surface states and interlayer in Au/n-Si/Ag diodes

The forward and reverse bias current-voltage (I-V), capacitance/conductance-voltage-frequency (C/G-V-f) characteristics of Au/n-Si/Ag Schottky barrier diodes (SBDs) were investigated by taking into account the effects of series resistance (Rs), surface states (Nss) and interlayer at room temperature. It is quite obvious that both C-V and G/ω-V plots showed reverse, depletion, and accumulation regions in a way that resemble those of good metal-insulator-semiconductor (MIS) type SBDs rather than those of MS type SBDs. The high value of ideality factor n = 1.907) was attributed to the existence of a native SiO2 interlayer, Nss and barrier inhomogeneity at M/S interface. The energy distribution profile of Nss was obtained from the forward bias I-V data by taking into account the voltage dependence of the effective barrier height (ΦB), n and Rs. The frequency dependent profiles of Nss and Rs were also obtained from C-V and G/ω-V data using Hill Colleman and Nicollian-Brews methods, respectively. The high values of C and G/ω at low frequency were attributed to the excess capacitance (Cex.) and conductance (Gex./ω) resulting from the Nss that could follow external ac signal. The value of ΦB obtained from the reverse bias C-V data for almost each frequency is higher than that of ΦB obtained from the forward bias I-V data. Such behavior of ΦB was attributed to the nature of measurement method. Experimental results confirmed that Nss and Rs are quite effective on the electrical characteristics in the existence of native or deposited interlayer.

Investigation of photo-induced effect on electrical properties of Au/PPy/n-Si (MPS) type schottky barrier diodes

Au/PPy/n-Si (MPS) type Schottky barrier diodes (SBDs) were produced and their current–voltage (I–V) characteristics were measured in the positive and negative bias regions at 300 K. The basic electronic quantities such as reverse-saturation current (Io), ideality factor (n), zero-bias barrier height (ФB0), series (Rs) and shunt resistances (Rsh) were obtained by using I–V data in total darkness and illumination (100 W/m2). The values of these parameters were found as 7.79 × 10−9 A, 5.41, 0.75 eV, 1 kΩ and 130 MΩ in dark) and 4 × 10−9 A, 4.89, 0.77 eV, 0.9 kΩ and 1.02 MΩ under illumination), respectively. Also the energy density distribution behaviors of surface states (Nss) have been acquired by calculation of effective barrier height (Фe) and ideality factor n (V) depending on voltage in total darkness and illumination. The values of Nss show an exponentially increase from the mid-gap of Si to the lower part of conduction band (Ec) for two conditions. The possible current conduction mechanisms were determined by plotting of the double logarithmic I–V plots in the positive voltage zone and the value of current was found proportional to voltage (I∼Vm). The high values of n and Rs were ascribed to the certain density distribution of Nss localized at semiconductor/PPy interface, surface conditions, barrier inequality, the thickness of PPy interlayer and its roughness. The open-circuit voltage of the photodiode was found as 0.36 V under 100 W/m2 illumination level. This is evidence that the fabricated sample is very sensitive to illumination. Therefore, it can be put into practice in optoelectronic industries as a photodiode or solar cells.