Thermionic Emission Method Research Articles

Electrical Properties of Laser Patterned Schottky Diode with ALD-Grown TiO2 Interlayer.

Heterojunction formation is the key to adjusting the electronic and optoelectronic properties of various semiconductor devices. There have been various reports on the formation and importance of semiconducting heterojunction devices based on metal oxides. Titanium dioxide (TiO2) is one of the metal oxides that has many unique properties. TiO2's importance is due to its physical and chemical properties such as large band gap, large permittivity, stability, and low leakage current density. In this context, we present the electrical properties of the metal-insulator-semiconductor (MIS) type-TiO2-based Schottky barrier diode (SBD) in the study. To create a thin layer of TiO2 on p-type silicon (p-type Si) patterned partially by the laser-induced periodic surface structure (LIPSS) technique, an atomic layer deposition (ALD) technique was used in the study. For comparison, the current-voltage (I-V) characteristics of the TiO2-based laser-patterned (LP) and nonlaser-patterned (non-LP) diodes were measured at 300 K and in the dark at ±5 V. Classical thermionic emission (TE) theory and Cheung functions were used to investigate the critical diode parameters of the diodes, including ideality factor (n), series resistance (Rs), and barrier height (Φb). The n values were obtained as 4.10 and 3.68 from the TE method and Cheung functions for the LP diode, respectively. The Φb values were found as 0.68 and 0.69 eV from the TE method and Cheung functions, respectively. According to experimental results, the laser patterning resulted in an increase in the Φb values and a decrease in the n values. After laser patterning, it was observed that the device worked effectively, and the ideality factor and barrier height values were improved. This study provides insight into the fabrication and electrical properties of TiO2-based heterojunction devices.

Optoelectronic properties of Au/n-type Si semiconductor structures with SiO2 interlayer

In this study, we investigated the effect of light intensity on electrical and photovoltaic properties using current-voltage (I–V) measurements at room temperature of Au/n-type Si structures with SiO2 interface layer. At each light intensity, the obtained main electrical characteristics such as ideality factors (n), barrier heights (Φbo), rectification ratios (RR), saturation currents (I0) and series resistances (RS) of Au/SiO2/n-type Si structures were calculated from both thermionic emission (TE) and Cheung methods using I–V measurements and compared to each other. Experimental results showed that while the n and I0 values increased with the increase in the light intensity, the Φbo and RR values decreased. While the ideality factor values obtained using the TE method ranged between 1.973 (at dark) and 2.250 (for 100 mW/cm2), these values were obtained between 3.227 and 3.482 using the Cheung method. At the same time, while the barrier height values obtained using the TE method ranged between 0.865 eV (at dark) and 0.817 eV (for 100 mW/cm2), these values were obtained between 0.773 eV and 0.742 eV using the Cheung method. It was observed that while the n values obtained from TE theory were smaller than the values obtained from the Cheung method, the Φbo values were larger than the values obtained from the Cheung function. Furthermore, for the Au/SiO2/n-type Si structures, the photovoltaic parameters such as short circuit current (Isc) and open circuit voltage (Voc) and photocurrent (Iph) were examined under dark, daylight and various light intensities (from 20 to 100 mW/cm2).

An artificial intelligence model estimation for functionalized graphene quantum dot-based diode characteristics

The use of artificial intelligence (AI) approaches, one of the most significant technological advances of the 21st century, to determine the diode parameters that can be obtained from Schottky diode characterization allows data to be collected, processed, analyzed, and results obtained faster than ever before, with high accuracy. It also supports the development of a selection and modeling tool for future studies and, most importantly, facilitates modeling implementation with faster and fewer experimental results. In this context, this study presents a machine learning model to predict diode parameters from current–voltage (I-V) measurements of polyethyleneimine-functionalized graphene quantum dots (GQDs)-based Schottky hybrid diode. This study used K-Nearest Neighbor, Random Forest (RF), Multilayered Perceptron, and Support Vector Machine algorithms. In research, the lowest model error of each model was compared, and the performance of the models obtained was evaluated. In addition, out of 30 diodes on the fabricated structure, the diode with the best rectification ratio (RR) was identified within a few seconds using machine learning, verified to be the same as the diode selected by the researchers, and the optimal estimation of RR and ideality factor was made from the diode parameters using the thermionic emission method. The experimental results were compared with machine learning models. Among these algorithms, the RF algorithm performed best with a mean square error value of 4.1 E-05 and an R-squared value of 0.999998. The success of RF depends on the characteristics of the dataset used, its size, and data distribution. The success rate of the RF algorithm is more successful in the 200 data sets used in this study. RF reduces overfitting by taking the average of multiple decision trees and is less sensitive to noise and outliers in the data. The results obtained will allow the development of a selection and modeling tool for future studies and, most importantly, facilitate modeling faster and with fewer experimental results, enabling the integration of AI into science.

Analysis of Current-Voltage Properties of Al/p-si Schottky Diode with Aluminium Oxide Layer

In our study, the effects of the metal oxide (aluminum oxide, Al2O3) thin film placed between the metal and the semiconductor on the diode's characteristics were investigated. The Al2O3 thin film was suitable for its growth on a p-type silicon substrate by the atomic layer deposition (ALD) technique. In this study, a diode structure with an oxide interlayer was fabricated. To investigate the electrical parameters of the fabricated Schottky diode, measurements of current-voltage (I-V) were carried out at room temperature and in the 5 V voltage range. Using the I-V measurements, diode parameters such as the barrier height (Φb), the ideality factor (n), and the current density (I0) were evaluated using the theory of thermionic emission (TE) and Cheung's method. Using the TE method and Cheung’s method, the approximate values of Φb, n parameters were calculated as 0.77 eV, 5.43, and 0.77 Ev, 5.97, respectively. According to calculations, the developed Schottky diode is a rectifier diode and has been determined to have photodiode properties. This research offers an understanding of the production and electrical characteristics of Schottky devices based on Al2O3.

Synthesis of TiO2 Nanotubes and Photodiode Performance

In this study, titanium dioxide (TiO2) nanotubes were produced by anodization method using glycerol-based electrolyte. Structural characterization was investigated with SEM images and XRD pattern. The rectifying properties of n-type semiconductor TiO2 nanotubes were investigated. Current-voltage (I-V) measurements of the Pt/TiO2 nanotubes/Ti device were made at room temperature, in the dark and under different illumination conditions. The basic diode parameters were calculated by using thermionic emission (TE), Cheung and Norde functions from the I-V measurements of the devices in dark conditions. The ideality factors and barrier height of the Pt/TiO2 nanotubes/Ti device were calculated 1.25 and 0.91 eV, respectively by the TE method. According to the results obtained, the Pt/TiO2 nanotubes contact has a rectifying feature. In addition, the photovoltaic properties of the devices were examined by making I-V measurements at illumination intensities between 30 and 100 mW/cm2. As a result, it has been evaluated that the device can also be used as a photodiode.

Machine learning approach for predicting electrical features of Schottky structures with graphene and ZnTiO3 nanostructures doped in PVP interfacial layer

In this research, for some different Schottky type structures with and without a nanocomposite interfacial layer, the current–voltage (I–V) characteristics have been investigated by using different Machine Learning (ML) algorithms to predict and analyze the structures’ principal electric parameters such as leakage current (I0), barrier height ({varphi }_{B0}), ideality factor (n), series resistance (Rs), shunt resistance (Rsh), rectifying ratio (RR), and interface states density (Nss). The interfacial nanocomposite layer is made by composing polyvinyl-pyrrolidone (PVP), zinc titanate (ZnTiO3), and graphene (Gr) nanostructures. The Gaussian Process Regression (GPR), Kernel Ridge Regression (KRR), Support Vector Regression (SVR), and Artificial Neural Network (ANN) are used as ML algorithms. The ML techniques training data are obtained using the thermionic emission method. Finally, by comparing the experimental and predicted results, the performance of the different ML algorithms in predicting the electrical parameters of Schottky diodes (SDs) has been compared to find the optimized ML algorithm. The ML predictions of basic electrical parameters by almost all algorithms are in good agreement with the actual values, while the SVR model has predicted closer values to the corresponding actual ones. The obtained results show that the quantity of the leakage current and Nss for MS type SD decreases, and φB0 increases with the interfacial layer usage, especially with graphene dopant.

Analysis of temperature dependent current-voltage and frequency dependent capacitance-voltage characteristics of Au/CoO/p-Si/Al MIS diode

In this study, the production and electrical characterization of Schottky circuit elements of Au/CoO/p-Si/Al (MIS) structure were investigated. Diode parameters such as the ideality factor (n), barrier height (Φb) and series resistance of Au/CoO/p-Si/Al structures were calculated from the forward bias I-V characteristics of the diode using the different methods such as Thermionic Emission method (TE), Cheung functions and Norde method. The variations of diode parameters from I-V measurements depending on the temperature were examined. In addition, diffusion potential (Vd), barrier height (Φb), Fermi energy level (Ef) and free carrier concentration (Na) were calculated from the C-V measurements of the diode. The variations of these values with frequency were examined from the C-V measurements.

Analysis of the temperature dependent electrical parameters of the heterojunction obtained with Au nanoparticles decorated perovskite strontium titanate nanocubes

Strontium titanate (STO) is one of the important members of the perovskite family and has a wide range of applications in optoelectronics. In this study, the rectifying properties of the heterojunction produced by gold (Au) decorated STO were investigated. Morphological and structural characterization of Au-STO material coated as a thin film, such as SEM, TEM, XRD was performed and the results showed that this structure is a suitable material for heterojunction structures. Current-voltage (I-V) measurements of Ni/Au-STO/n-Si heterojunction devices obtained by coating the Si surface with the spin coating method of Au-STO were performed in the dark and between 60 and 400 K. Additionally, capacitance-voltage (C-V) measurements of the device were made under the same conditions and between 80 and 360 K. Basic diode parameters such as ideality factor (n), barrier height (Фb), series resistance (Rs) were determined from the I-V characteristic of the device using Thermionic emission (TE), Cheung and Norde functions. According to the TE method, the ideality factor of the device was calculated as 1.12 and the barrier height was 0.65 eV at 300 K. The obtained results showed that the Ni/Au-STO/n-Si heterojunction has rectifying properties. In all three calculation methods, as the application temperature increased, the ideality factor of the device decreased and on the other hand, the barrier height increased. This change showed the temperature sensitivity of the Au-STO/n-Si junction.

Structural role of double layer amphoteric oxides forms on electrical conductivity: PbO/zinc oxide semiconductor

We have investigated the electrical properties of PbO/Zinc Oxide double-layer semiconductor (DLS) diodes such as series resistance (), ideality factor (), and barrier height (). The samples were manufactured by using an evaporation technique at room temperature. To obtain their main electrical parameters, current-voltage (I–V) measurements have been performed in the dark and at room temperature. In the study, we examined two diodes to evaluate the electrical characteristics of PbO/Zinc Oxide double-layer semiconductor (DLS) diodes using the thermionic emission (TE) theory, Norde’s method, and Cheung’s functions. While n, and values of Diode 1 were found to be 4.02, 0.739 eV, and 1.506. 10−8 A respectively, the same values of Diode 2 were calculated as 4.14, 0.724 eV, and 2.65.10−8 A, respectively, by using the TE method. The values of n, and were also calculated using the Cheung’s method, and they were found to be 10.048, 0.549 eV, and 4.058 respectively, for Diode 1, while these values were calculated as 8.116, 0.659 eV, and 7.799 respectively, for Diode 2. and values are also ascertained as for Diode 1 and for Diode 2, for Diode 1 and for Diode 2 using Norde Method, respectively. The forward bias I–V characteristics were used to obtain the energy distribution of the interface state density considering the effective barrier height’s bias dependence. The change observed in the interface state density’s magnitude ranged between and The evaluated series resistance indicates the product of mobility and free carrier concentration, ideality factor is a measure of how closely the diode follows the ideal diode equation, and barrier height also depends on the concentration of carriers in PbO/Zinc Oxide double-layer semiconductors.

The heterojunction diode application of mesoporous graphitic carbon nitride (mpg-C3N4)

In this study, morphological properties and Schottky diode application of mpg-C3N4 material were investigated. XRD, SEM and TEM analyzes of this material were performed. When the SEM image is examined, it is seen that mpg-C3N4 particles are coated on the surface homogeneously. The p-Si crystal was used as the base material and mesoporous graphitic carbon nitride material mpg-C3N4 was coated on the crystal with spin coating. Thus, reference and mpg-C3N4/p-Si heterojunctions were fabricated. Using the current-voltage (I–V) measurements of the diode, the ideality factory (n) and barrier height (Φb) values were calculated at the room temperature. These values of Ni/mpg-C3N4/p-Si/Al heterojunction diode were determined as n = 1.25 and Φb = 0.83 eV by the Thermionic Emission (TE) method. Furthermore diode parameters (n, Φb and series resistance (Rs) were determined with Cheung and Norde functions. Also capacity-voltage (C–V) measurements of this device were taken for different frequency values. Using this measurements carrier concentration (Na), barrier heights (Φb), Fermi energy level (Ef) and diffusion potential (Vd) values were determined.

The role of molybdenum trioxide in the change of electrical properties of Cr/MoO3/n-Si heterojunction and electrical characterization of this device depending on temperature

In this study, the molybdenum trioxide as a chemical compound with the formula MoO3 was coated between chromium (Cr) metal and n-type semiconductor (n-Si) by thermal evaporation. Using this method, Cr/MoO3/n-Si/Al heterojunction was obtained. With the thermionic emission (TE) theory, the ideality factor (n) for the reference Cr/n-Si/Al metal-semiconductor (MS) device was calculated as 1.88 and the barrier height (Φb) was calculated as 0.59 eV. On the other hand, the ideality factor for six (D1-D6) Cr/MoO3/n-Si/Al heterojunction devices obtained with MoO3 nanopowder was calculated between 1.61 and 1.69, and the barrier height was calculated as 0.69 eV, respectively. According to these results, MoO3 layer made the device's current transmission mechanism behave ideally and increased the barrier height. Current-voltage (I–V) measurements depending on temperature were performed for D1 named Cr/MoO3/n-Si/Al device, which provided the best results. Electrical parameters, such as n, Φb and series resistance (Rs), by the TE method, Cheung and Norde functions were calculated using I–V characteristic taken from the 100 K–400 K temperature range. According to the results obtained, the values of n and Rs decreased and the barrier height increased in the heterojunction device due to the increase in the temperature value. When the results were evaluated, it was observed that the current transmission of the Cr/MoO3/n-Si/Al device was compatible with the applied temperature and a significant and regular change in the temperature-dependent I–V characteristics. This finding suggests that Cr/MoO3/n-Si/Al heterojunction obtained with MoO3 is a good option for thermal sensitivity applications.

Electrical property investigation of the Au/n-Si and Au/PVA+benzimidazole Co complex/n-Si diodes under ultraviolet illumination

Polyvinyl alcohol (PVA) was doped using the di[1-(2-ethoxyethyl)-5-nitrobenzimidazole] cobalt dichloride and this polymeric composite was used as an interface in Au/n-Si diodes. The basic electrical properties of these fabricated Au/n-Si (MS) and Au/PVA+Co complex/n-Si (MPS) diodes were examined measuring voltage-dependent current (I(V)) data in various ultraviolet illumination intensities and room temperature. Electrical parameters of the MS and MPS diodes were calculated by thermionic emission, Norde, and Card & Rhoderick method. It was found that the ideality factor (n) values of the MS diode increased from 6.7 to 13.4 while the MPS ones increased from 3.4 to 7.5 with increasing illumination. Also, the photo-responsivity (PR) of MPS diode was obtained for P = 50 mW/cm2 (365 nm UV) as 0.29 A/W at − 5.00 V and 4.01 mA/W at 0 V.

Temperature dependent electronic transport properties of heterojunctions formed between perovskite SrTiO3 nanocubes and silicon

In this study, synthesized strontium titanate (SrTiO3) nanocubes were coated on n-Si semiconductor by spin coating to obtain a heterojunction device. Transmission electron microscopy image, scanning electron microscope image and x-ray diffraction patterns of thin film of SrTiO3 nanocubes coated on Si surface were taken for structural and morphological characterization of the material. The basic device parameters such as ideality factor (n) and barrier height (Φb) values of the reference Ni/Si/Al metal–semiconductor diode and of the Ni/SrTiO3/n-Si/Al heterojunction devices were calculated with the thermionic emission (TE) theory. The n and Φb values of the reference Ni/n-Si/Al device were calculated as 1.93 and 0.60 eV, respectively at room temperature. On the other hand, lower n and higher Φb values of Ni/SrTiO3/n-Si/Al heterojunction device were calculated as 1.34 and 0.63 eV, respectively. With these results, the current–voltage (I–V) measurements of the heterojunction device in the 80–400 K range were taken and the n, Φb, series resistance (Rs) values were calculated depending on the temperature by using different methods such as TE, Cheung and Norde functions. It was observed that while the temperature values decreased, n and Rs values of the device increase and Φb value decreases. The results obtained showed that the charge transport system is compatible with TE. The device parameters calculated from the Cheung and Norde methods also showed similar changes depending on the temperature. However, since the calculation method is different according to the TE method, different values were obtained in the device parameters. In addition, the curve Φb and (1/n)−1 against (1/2kT) was observed in accordance with the double Gauss distribution of the barrier heights. It was seen that the reverse bias I–V characteristics of the Ni/SrTiO3/n-Si/Al can be used in thermal sensors applications.

Synthesis of CuO–graphene nanocomposite material and the effect of gamma radiation on CuO–graphene/p-Si junction diode

Here, we introduce high-quality CuO–Graphene nanocomposite synthesis by hydrothermal method and used it as the interfacial layer to investigate radiation resistance in metal/interlayer/semiconductor (MIS) junction diode structure. In order to determine the effect of the nanocomposite layer on the electrical characteristics of Al/CuO–Graphene/p-Si/Al MIS junction diode, the current–voltage (I–V) measurements were performed at room temperature. The main electrical parameters of the junctions such as ideality factor (n), barrier height (Φb) were calculated using the thermionic emission (TE) theory and the results were compared with reference Schottky Diode (SD). The Φb and n values were calculated as 0.70 eV, 1.93 and 0.72 eV, 1.75 for reference SD and CuO–Graphene/p-Si MIS junction, respectively. The n value of the device reduced in the presence of the nanocomposite layer between the metal and the semiconductor. In addition, the Φb and series resistance (Rs) parameters were calculated from I–V measurements using Norde functions and the results were compared with the TE method. Furthermore, to determine the radiation tolerance property of the devices, gamma radiation was applied and the electrical parameters were evaluated for unirradiated and irradiated cases. The results showed that the fabricated devices may have various applications; thanks to radiation tolerance property. To the best of our knowledge, there is no research available regarding the exposure of CuO–Graphene thin films to gamma-ray irradiation studied using the I–V technique. Therefore, we believe that this study can make an important contribution to the literature.

Analysis on the temperature dependent electrical properties of Cr/Graphene oxide-Fe3O4 nanocomposites/n-Si heterojunction device

In this study, the Cr/n-Si/Al and Cr/Graphene oxide-Fe3O4 nanocomposites (GO-Fe3O4)/n-Si/Al heterojunction devices were fabricated and their Schottky diode performances were studied comparatively. In the first step, the GO-Fe3O4 nanocomposites were synthesized and the film characterization was carried out via XRD, SEM and AFM analysis methods. The results showed that the performance of the Cr/GO-Fe3O4/n-Si/Al device was better than that of Cr/n-Si/Al. For example, experimental ideality factors and the barrier heights were determined as 3.75 and 0.70 eV for Cr/n-Si/Al while they were found as 1.28 ve 0.63 eV for Cr/GO-Fe3O4/n-Si/Al heterojunction device. Next, we examined the electronic properties of the Cr/GO-Fe3O4/n-Si/Al heterojunction device as a function of temperature and the device performance of Cr/GO-Fe3O4/n-Si/Al heterojunction was evaluated by the analysis of I-V characteristics. To examine the electrical features of Cr/GO-Fe3O4/n-Si/Al heterojunction device, I-V measurements were studied between 100 K and 360 K in steps of 20 K. Next, the device parameters such as barrier height, ideality factor and series resistance were calculated by using Thermionic Emission (TE) and Cheung method. As a result of these measurements, it was found that the barrier height and ideality factor of the Cr/GO– Fe3O4/n-Si/Al heterojunction were depended on temperature, in which the barrier height increases while the ideality factor decreases with increasing temperature. According to calculations done by TE, the barrier height and ideality factor of Cr/GO-Fe3O4/n-Si/Al heterojunction device were found to be 0.26 eV and 2.46 eV at 100 K to 0.73 eV and 1.28 eV at 360 K. Additionally, the capacitance-voltage characteristics of the mentioned structure were analyzed at room temperature.

Characterization of GZO thin films fabricated by RF magnetron sputtering method and electrical properties of In/GZO/Si/Al diode

The main focus of this work is the structural and optical characterization of Ga-doped ZnO (GZO) thin film and determination of the device behavior of In/GZO/Si/Al diode. GZO thin films were deposited by RF magnetron sputtering technique from single target. The structural and morphological properties of GZO film were investigated by X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analysis (EDS) measurements. Optical properties of the film were determined with transmission measurement. Device characterization of In/GZO/Si/Al diode were done with the analysis of temperature dependent current voltage (I–V) measurement. The current conduction mechanism was investigated with the Thermionic Emission (TE) method. The deviation from the pure TE method was observed and this deviation was analyzed under the assumption of Gaussian Distribution (GD) of barrier height (TE emission with GD). The mean standard deviation and zero bias barrier height were calculated as 0.0268 (about %3) and 1.239 eV, respectively. Richardson constant was found to be as 115.42 A/cm2 K2 using the modified Richardson plot. In addition, series resistance Rs was obtained using Cheung’s function. Finally, the interface state densities Dit were determined by using the forward bias I–V results.

Influence of Annealing Temperature on Structural and dc Electrical Properties of SnO2 Thin Films for Schottky Barrier Diodes

This paper reports about the influence of annealing temperature on the structural, morphological, optical and electrical properties of SnO2 thin films prepared by the spin-coating method. The structural analysis reveals the presence of rutile SnO2 with tetragonal structure and its defects are reduced in higher annealing temperatures. SEM images show that the size of the grains was improved due to increase in annealing temperature. From UV-visible analysis, band gap energy (Eg), refractive index (n), and extinction coefficient (k) are estimated. The band gap energy increases from 3.46 to 3.54 eV with annealing temperatures. dc analysis shows that the Arrhenius conduction mechanism has a profound influence on the electrical conductivity and varies in the range 1.08–6.80 × 10− 8(Ω cm)− 1 with annealing temperature. The Al/n-SnO2/p-Si Schottky barrier diode parameters such as ideality factor (n), barrier height (4ΦB), leakage current (I0) and series resistance (Rs) were studied by the I-V method as a function of annealing temperature as per the Thermionic Emission method (TE). The barrier height varies from 0.84 to 0.73 eV and the device ideality has improved at higher annealing temperature.

Impact of annealing treatment on structural and dc electrical properties of spin coated tungsten trioxide thin films for Si/WO3/Ag junction diode

We report on the effect of the thermal annealing on structural and electrical properties of p-Si/n-WO3/Ag junction diode. According to the XRD pattern, the WO3 films exposed that the crystalline phase transformation of monoclinic to orthorhombic structure for an increasing annealing temperature. The SEM images show an abrupt change in the plate like grain growth and surface morphology. From the UV–visible analysis, the band gap energy decreases for the higher annealing temperature. The dc electrical characterization shows that the conductivity (σdc), activation energy (Ea) and pre-exponential factor (σ0) values vary function of temperature. The Si/WO3/Ag contact junction diode parameters of ideality factor (n), barrier height (ΦB), leakage current density (J0) and series resistance (Rs) were examined by the J-V method, Cheung's and Norde functions as a function of annealing temperature according to the thermionic emission method (TE). The values of n and ΦB decrease with increasing annealing temperature and better the device performance on an optimized annealing temperature at 873K. The temperature dependent of experimental n and ΦB revealed the presence of inhomogeneity at WO3-Ag interface. This behavior is modeled by assuming the existence of Gaussian distribution (GD) of barrier heights in temperature range 303–423K.

Thermometry of Filamentary RRAM Devices

Since thermal effects play a major role in filamentary RRAM devices, we compare the two localized thermometry methods developed for such devices. One method is based on short-pulsed measurements and the other on the measurement of minority-carrier injection from the filament into a semiconductor electrode by thermionic emission. We carried out and compared the measurements on the same functional oxide layer. Both methods indicate that the filament temperature is at least $\sim 550$ K during device operation. Furthermore, comparison between the measured thermal resistance and the thermal simulations of both techniques shows that under the conditions of low forming current compliance ( $\sim 10~\mu \text{A}$ ), the filament dimensions are below $\sim 5$ nm. We show that the thermionic emission method is useful for high-resistance ( $>100~\text{k}\Omega )$ devices operating at low-power conditions ( $ ), whereas the pulsed thermometry is more suitable for lower resistance devices ( $ operated above 1 $\mu \text{W}$ . The average thermal resistance measured by the pulse technique decreases with applied power. Our simulations indicate that the expansion of the heated zone surrounding the filament can explain the observed reduction in thermal resistance with applied power. The underlying physics of the two methods is discussed.

Temperature dependent of electrical characteristics of Au/n-GaAs/In Schottky diode with In2S3 interfacial layer obtained by using spray pyrolysis method

A study on Au/n-GaAs Schottky barrier diodes parameters with and without thin In2S3 thin films, fabricated on n-type GaAs grown by Spray Pyrolysis Method (SPM), has been made. The film nanostructure features have been characterized by XRD, SEM and EDAX techniques. The Au/n-GaAs/In and Au/In2S3/n-GaAs/In junctions are investigated the electrical characteristics with Current-Voltage (I–V) measurements at room temperature. The Current-Voltage-Temperature (I–V–T) and Capacity–Voltage–Temperature (C–V–T) characteristics of Au/In2S3/n-GaAs/In structure are determined in the temperature wide range 300–20 K with 20 K steps. Some electrical parameters such as ideality factor n, zero bias barrier height ΦBo and series resistance RS are extracted from I–V–T curves using Thermionic Emission (TE) method and modified Norde functions. It is observed that the barrier height decreases and the ideality factor increases with the decrease temperature. Such behavior is attributed to barrier inhomogeneities by assuming a Gaussian distribution of barrier heights at the interface for two regions. Furthermore, from the C–V–T measurement of the structure ΦB(CV), donor concentration (ND), Fermi level (EF) and diffusion potential (VD) have been calculated in the temperature range of 300–20 K at 500 kHz applied frequency.