Norde Functions Research Articles

The effect of radiation on the forward and reverse bias current–voltage (I–V) characteristics of Au/(Bi4Ti3O12/SiO2)/n-Si (MFIS) structures

Determining the radiation effects on the basic electrical parameters of the fabricated high-dielectric MFIS structures, they were exposed to the high-energy 60Co γ-rays. For this purpose, the values of ideality factor (n), barrier height (ΦB) and series resistance (Rs) were extracted from the forward bias I–V data before and after irradiation by using various methods such as standard thermionic emission (TE) theory, Cheung’s and Norde functions. Additionally, the energy-dependent profile of surface states Nss was extracted by considering voltage dependence of n, ΦB and Rs and compared each other. Experimental results show that the reverse saturation current (Io), n and Rs values increase with increasing radiation dose, but ΦB decreases. When the value of Rs is considered in the calculation of Nss, they were found to be considerably decreased. The observed low discrepancies between Nss after irradiation show that the use of a high-dielectric ferroelectric interlayer leads to an increase in the resistance of MS to radiation. It is more important to fabricate radiation-resisted electronic device, especially in the satellites due to hard radiation in space. As a result, Nss, Rs and the existence of interlayer are more effectual on the I–V characteristics which must be considered in the electrical parameter calculation.

Investigation of the effect of different Bi2O3–x:PVA (x = Sm, Sn, Mo) thin insulator interface-layer materials on diode parameters

In this work, Au/4H–SiC Schottky diodes with different Bi2O3–x:PVA (x = Sm, Sn, Mo) thin insulator interface layer were produced for the fabrication of metal/insulator/semiconductor (MIS) structures. The effect of different Bi2O3–x:PVA interfacial layer deposited between metal and semiconductor on important optical and electrical parameters of Schottky diodes was investigated. The main electrical parameters of the prepared structures such as the saturation current (I0), the barrier height (ΦB0), ideality factor (n), and series and shunt resistance (Rs and Rsh) were obtained from the I‒V characteristics. The discrepancies in these parameters can be ascribed to the use of different nanomaterials as an interlayer. Moreover, the values of n, ΦB0, and Rs were also extracted by using Cheung and Norde functions and obtained results were compared with each other. The energy dependence of interface states [Nss vs (Ec − Ess)] was investigated by taking into account the voltage dependence of Φe(V) and n(V). In addition, Ln(I)–Ln(V) plots were drawn to specify the possible current transport mechanisms of the prepared structures. Experimental results show that the Schottky structures with (Bi2O3–Sn:PVA) and (Bi2O3–Sm:PVA) interlayers yield higher RR and Rsh values and lower Io values. This provides an evidence to performance increase in MS structures.

Co/aniline blue/silicon sandwich hybrid heterojunction for photodiode and low-temperature applications

The temperature dependence of the current–voltage and room temperature capacitance–voltage measurements of Co/aniline blue/ n-Si sandwich-type rectifying device was investigated.Furthermore, the effects of the illumination on the current–voltage measurements were tested with 100 mW/cm2 light intensity, and it was seen that Co/aniline blue/ n-Si sandwich-type device showed a clear response to illumination, and it may be a candidate for solar cells or photodiode applications. The rectifying device parameters, such as the barrier height (Ф), the ideality factor ( n), the rectification ratio, and the series resistance ( Rs), were obtained as a function of temperature using thermionic emission, Cheung function, and Norde function. The interface state densities versus energy were obtained. The Richardson constant ( A*) obtained from the In( Io/ T2) versus 1000/ T plot was much less than the theoretical value for n-Si. The mean Schottky barrier height[Formula: see text] and the standard deviation ( σo) were calculated using the apparent Schottky barrier height Фap versus 1/2 kT plot. So, it has been found to be 1.08 eV and 0.15 V (260–460 K) and 0.79 eV and 0.10 V (100–260 K), respectively. The results were discussed based on the presence of two Gaussian distributions of Фb potential in the contact area of Co/aniline blue/ n-Si/Al device.

Analysis of current–voltage and capacitance–voltage characteristics of Zr/p-Si Schottky diode with high series resistance

Zr/p-Si Schottky diode was fabricated by DC magnetic sputtering of Zr on p-Si. Zr rectifying contact gave a zero bias barrier height of 0.73 eV and an ideality factor of 1.33 by current–voltage measurement. The experimental zero bias barrier height was higher than the value predicted by metal-induced gap states (MIGSs) and electronegativity theory. The forward bias current was limited by high series resistance. The series resistance value of 9840 [Formula: see text] was determined from Cheung functions. High value of the series resistance was ascribed to low quality ohmic contact. In addition to Cheung functions, important contact parameters such as barrier height and series resistance were calculated by using modified Norde method. Re-evaluation of modified Norde functions was realized in the direction of the method proposed by Lien et al. [IEEE Trans. Electron Devices 31 (1984) 1502]. From the method, the series resistance and ideality factor values were found to be as 41.49 [Formula: see text] and 2.08, respectively. The capacitance–voltage characteristics of the diode were measured as a function of frequency. For a wide range of applied frequency, the contact parameters calculated from [Formula: see text]–[Formula: see text] curves did not exhibit frequency dependence. The barrier height value of 0.71 eV which was in close agreement with the value of zero bias barrier height was calculated from [Formula: see text]–[Formula: see text] plot at 1 MHz. The values of acceptor concentration obtained from [Formula: see text]–[Formula: see text] curves showed consistency with actual acceptor concentration of p-Si.

Analyzed electrical performance and induced interface passivation of fabricated Al/NTCDA/p-Si MIS–Schottky heterojunction

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.

Improving the Electronic Properties of Au/n-Si Type Schottky Junction Structure With Graphene-PVP Nano-Thin Film by Using the I-V, C−2-V and G/ω-V Characteristics

The letter reports the performance assessment of Au/ n -Si type Schottky Junction Structure (SJS) with and without the graphene-PVP layer, classified as SJS1 and SJS2 devices. The electronic parameters by using the developed LabVIEW based program were calculated from raw data of I-V, C-V and G/ω-V measurements at room temperature. According to Thermionic Emission (TE) theory, the graphene-PVP layer significantly modified the barrier height than the other structure. Using the Ohm's Law, it is found that the $R_{sh}$ magnitude increases, while the $R_{s}$ magnitude decreases for SJS2, according to SJS1 type device. Alternatively, using Cheung's and the modified Norde functions for the accuracy and reliability of the results, the obtained n , $\phi _{Bo}$ , $R_{s}$ values by both equations are in good agreement. Using the C−2-V and G/ω-V characteristics, the magnitudes of the electronic parameters, such as $\phi _{Bo}\,_{{\rm{(C-V)}}}$ , $V_{bi}$ , $V_{D}$ , $N_{D}$ , $E_{F}$ , $R_{s}$ , etc., for the devices were calculated to supply more information. Also, the $C_{i}$ and $C_{ox}$ magnitudes were calculated 1.299 × 10−10 F and 1.192 × 10−10 F at 3 V and then, the interface layer thicknesses were obtained as 2.08 nm and 68.8 nm for SJS1 and SJS2, respectively. It can be concluded that the graphene-PVP layer significantly affects the quality and performance of Au/ n -Si type SJS devices.

Electrical and photoresponse characteristics of 8-(1H-indol-3-ylazo)-naphthalene-2-sulfonic acid/n-Si photodiode

• 8-(1 H -indol-3-ylazo)-naphthalene-2-sulfonic acid (INSA) was synthesized. • The Au/INSA/n-Si/Al diode parameters were calculated in dark and under illumination. • The INSA film modifies the interfacial barrier height of classical junction. • The fabricated device is promising for photodiode applications. In this paper, of primary interest is to synthesis 8-(1 H -indol-3-ylazo)-naphthalene-2-sulfonic acid (INSA) and to evaluate the main parameters of Au/INSA/n-Si/Al diode in dark and under illumination. Different techniques are used for interpreting the proposed INSA chemical structure. The dark current-voltage measurements were achieved in the temperature range of 293−413 K. It is noticed that INSA films modify the interfacial barrier height of classical Au/n-Si junction. At low applied voltages, the I–V relation shows exponential behavior. The values ideality factor, n , and the barrier height, φ , are improved by heating. The abnormal trend of n and φ is discussed, and a homogenous barrier height of 1.45 eV is evaluated. The series resistance is also calculated using Norde's function and it changes inversely with temperature. The space charge limited current ruled with exponential trap distribution dominates at relatively high potentials, trap concentration and carriers mobility are extracted. The reverse current of the diode has illumination intensity dependence with a good photosensitivity indicating that the device is promising for photodiode applications.

The Aromatic Thermosetting Copolyester for Schottky Diode Applications in a Wide Temperature Range

The aromatic thermosetting copolyester (ATSP) was deposited on p-Si substrates by the spin coating method, and the thickness of thin film layer was about 50 nm. It was employed to fabricate metal-polymer-semiconductor (MPS) heterojunctions as interfacial layers between metal contact and p type Si. The morphological properties of the Al/ATSP/p-Si heterojunctions were investigated by Scanning Electron Microscope (SEM) and an Atomic Force Microscope. The electrical characteristics of the heterojunctions were analyzed within a wide temperature range between 100 K and 500 K and frequency range. The current–voltage–temperature (I–V–T) characteristics of the MPS heterojunctions were explained by the Thermionic Emission (TE) theory and Norde function. Critical electrical parameters including leakage current (I0), barrier height (Φb) and ideality factor (n) and series resistance (Rs) were calculated by I–V–T characteristics in dark conditions. The value of n and Φb was obtained as 2.56 and 0.78 eV at 300 K. The n and Φb values were obtained as strong function of the temperature depending on barrier inhomogeneity. The temperature dependent rectification ratios of the Al/ATSP/p-Si heterojunctions were calculated and discussed in the details considering effective operating temperatures. The capacitance–voltage (C–V) and conductance–voltage (G–V) characteristics were measured at 300 K. To obtain Fermi energy (EF), donor concentration (Na), maximum electric field (Em), Φb and interface states (Nss), were performed on the bases of voltage and frequency at 300 K. From the electrical analysis results, it is proposed that the MPS device can be employed in electronic devices at low and high temperatures.

Fabrication of Schottky barrier diodes with the lithium fluoride interface layer and electrical characterization in a wide temperature range

In this study, lithium fluoride (LiF) was deposited as an interface layer between metal and p-type silicon (p-Si) wafer by thermal evaporation and, thus, the Cr/LiF/p-Si/Al Schottky type diode structures were obtained. The basic diode parameters such as ideality factory (n) and barrier height (Φb) were calculated using the thermionic emission (TE) theory. The results showed that the ideality factors and barrier height values of the Cr/LiF/p-Si/Al devices varied from 1.37 to 1.48 eV and 0.74–0.79 eV at 300K, respectively. These value for the reference Cr/p-Si/Al device, which was obtained under the same conditions with the Cr/LiF/p-Si/Al devices, were 1.75 and 0.69 eV, respectively. The presence of the LiF layer between the metal and the semiconductor reduced the ideality factor of the device and increased the barrier height. These results were evaluated and the I-V measurements of a relatively good device of a Cr/LiF/p-Si/Al Schottky barrier diode called D2 were carried out within a wide temperature range. Various basic diode parameters such as n, Φb and series resistance (Rs) of the device were calculated from I-V measurements by using different methods such as TE, Cheung and Norde functions within the 280 K–400 K range. It was determined that as the temperature value increased, series resistance and ideal factor decreased. However, the barrier height of the device increased. All these obtained results show that the current transmission mechanism is compatible with the TE theory. In addition, Fermi energy level, diffusion potential, carrier concentration and barrier height were calculated from the capacitance-voltage (C-V) measurements of the D2 device as a function of frequency at 300 K.

Interface controlling study of silicon based Schottky diode by organic layer

The organic layer-on- insulator–semiconductor structures have attracted most attention owing to their great significance on technological applications. The interface of silicon based metal/semiconductor diode was improved using an organic layer. In this study, Sn/p-Si MS contact and Sn/C14H15N3/p-Si MIS heterojunction were fabricated via spin coating method. The electrical parameters of both devices have been investigated, and compared using the current–voltage (I–V) and capacitance–voltage (C–V) data at room temperature. The ideality factor of diodes with and without organic interfacial layer was calculated as 1.33 and 1.28, respectively. The values of barrier height were estimated as 0.69 and 0.81 eV for the MS and MIS type structure, respectively. Additionally, the values of series resistances for both diodes were determined as 1.27 and 1.19 kΩ from Norde functions, respectively. The barrier height values were also examined using the reverse bias C−2–V characteristics for both diodes, and compared with results obtained from I to V data. The experimental results confirmed that the barrier height of Sn/C14H15N3/p–Si MIS structure is considerably higher than that of traditional Sn/p-Si MS diode. The performance and quality of these type devices could be improved and controlled by inserting the organic interfacial layer between the metal and semiconductor.

Photoresponsivity and photodetectivity properties of copper complex-based photodiode

Spin coated Cu(II) complex thin layer onto p-Si substrate was used in photodiode fabrication. The structural properties of novel synthesized Cu(II) complex were investigated using different techniques. The single crystal X-ray diffraction (sc-XRD) technique confirms the Cu(II) complex containing 2-mesityl-1H-benzo[d]imidazole ligands and two chloride ligands have a highly distorted cis-square-planar geometry. The thermogravimetric analysis (TGA) shows that the Cu(II) complex is stable up to 248 °C. Also, the current-voltage measurements were performed to investigate the characteristic of photodiode based on copper complex in darkness and under solar simulator. The fundamental electrical parameters of fabricated diode were obtained using Thermionic theory and modified Norde function. The manufactured device exhibits a good response to light with the defined rise and fall time of 351 ms and 622 ms under 100 mW cm−2 solar illumination, respectively. Furthermore, frequency dependent capacitance and conductance measurements were performed in dark and under illumination. The obtained results suggest that prepared photodiode based on Cu(II) complex could be used for organic light detection in different optoelectronic applications as photodetector, photocapacitor, and photoconductor.

Chemical, electrical and carrier transport properties of Au/cytosine/undoped-InP MPS junction with a cytosine polymer

An Au/cytosine/undoped-InP metal/polymer/semiconductor (MPS) junction was prepared with a cytosine polymer layer by spin coating and e-beam processes. The chemical properties were explored with X-ray photoelectron spectroscopy (XPS) approach and the results confirmed that the cytosine thin film was grown on undoped-InP surface. The electrical properties of MPS were compared with the Au/undoped-InP Schottky junction (SJ) results. Higher barrier height (BH) was achieved for the MPS junction (0.63 eV) than the SJ (0.57 eV), which demonstrates the BH was influenced by the cytosine interlayer. The BH, ideality factor and series resistance of SJ and MPS junction were derived by Chenug's, Norde functions and ΨS-V plot. The derived BH by these three approaches were almost equal with one another that suggests their steadiness and validity. The Poole-Frenkel emission governed the reverse current conduction mechanism in the lower bias region, whereas Schottky emission was ruled in the higher bias region for both the SJ and MPS junction. Analysis demonstrates that such cytosine polymer layers have prospective for use in organic and inorganic electronic devices.

Comparative investigation on electronic properties of metal-semiconductor structures with variable ZnO thin film thickness for sensor applications

In this work, AuPd/n-GaAs and Ag/n-GaAs metal–semiconductor structures, which is known as Schottky Junction Structures (SJSs), with various ZnO thin film thickness (25–250 nm) classified as Group AuPd and Group Ag were produced to investigate electronic properties on SJSs. The current-voltage (I–V) characteristics of SJSs operating in their forward and reverse regions operating at ±3 V were measured at room temperature (295 K). The electronics parameters such as the series resistance (Rs), the shunt resistance (Rsh), the ideality factor (n) and the barrier height (ΦB0) were calculated by using thermionic emission (TE) theory, Ohm's law, Cheung and Cheung's function and modified Norde's function. Labview® based characterization tool developed to calculate the electronic parameters. The results were compared according to the various thicknesses and different rectifier contacts. Experimentally, if the results are analysed for each group, a (gradual) decrease in ZnO thicknesses is caused by an increase in the values of n, ФB0, RR. In addition, the Rsh values were significantly increased while the Rs values were almost close to each other. As the ΦB0 values, while compatible with the values found in the Cheung and Cheung's function, they are slightly higher than the values found in the TE theory. On the other hand, due to the voltage-dependent barrier height and nature of the used method, ФB0 values from modified Norde's function are a little higher than the TE theory. Finally, it can be clearly seen that electronic parameters of SJSs based on sensor applications can be arranged with various thicknesses according to extracted results.

Structural, Chemical and Electrical Properties of Au/La2O3/n-GaN MIS Junction with a High-k Lanthanum Oxide Insulating Layer

This paper demonstrates the role of high-k La2O3 on the electrical performance of the Au/n-GaN Schottky junction (SJ) as an insulating layer between the Au and n-GaN films. First, the La2O3 is deposited on a n-type GaN surface by e-beam technique and analysed for its structural and chemical properties with x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) approaches. XRD and XPS results confirmed the growth of La2O3 on the n-GaN surface. Then, the Au/La2O3/n-GaN metal/insulator/semiconductor (MIS) junction is fabricated and analysed for its electrical properties and compared with the SJ electrical results. The MIS junction exhibits a good rectifying nature with a low leakage current compared to the SJ. Experimental findings reveal a higher barrier height obtained for the MIS junction than the SJ, suggesting that the barrier height is altered by the La2O3 insulating layer. Also, the barrier heights are estimated by Cheung’s, Norde functions and ΨS–V plot, and the values are nearly matched with each other, indicating the techniques used here are valid. The extracted interface state density (NSS) of MIS junction is lower than the SJ, implying the La2O3 insulating layer plays a vital role in the decreased NSS. Experimental findings confirmed that the Schottky emission governs the reverse current in SJ. However, for the MIS junction, the Poole–Frenkel and Schottky emissions are the dominant current conduction mechanisms in the lower and higher bias regions.

Electrical properties of Sn/Methyl Violet/p-Si/Al Schottky diodes

Abstract We studied the electrical characteristics of a Schottky diode with organic components Sn/methyl-violet/p-Si/Al. We investigated the diode’s current-voltage (I-V), capacitance-voltage (C-V), and capacitance-frequency (C-f). From ln(I)-V plots of the diodes, ideality factor (n) and saturation current (I0) were calculated. Moreover, the barrier height (Φb) and series resistance (RS) were calculated with Cheungs’ and Norde functions. Results shown that at the methyl-violet layerplayed an important role in electrical properties such as series resistance, barrier height, ideality factor and capacitance

The current–voltage and capacitance–voltage characterization of the Au/Methylene Blue/n-GaAs organic-modified Schottky diodes

We report the electrical properties of the Au/n–GaAs devices with and without thin organic interface layer. Methylene blue (MB) is a heterocyclic aromatic chemical compound with the molecular formula C16H18N3SCl. The MB layer was formed by spin coating technique on chemically cleaned gallium arsenide (GaAs) substrate. The current–voltage (I–V) and the frequency dependent capacitance–voltage (C–V) characteristics of the Au/MB/n–GaAs metal-insulator-semiconductor (MIS) and Au/n–GaAs metal-semiconductor (MS) devices have been investigated at room temperature. The MS and MIS devices I–V characteristics the showed a good rectification, and they were analyzed based on the thermionic emission (TE) theory. The ideality factor (n) and the barrier height (Φb(IV)) from the I–V characteristics was determined as 1.131±0.006 and 0.782±0.005 eV for MS device and 1.336±0.057 and 0.950±0.008 eV for MIS device, respectively. A Cheung’s method and modified Norde's function has been used to extract the parameters including the (Φb) and the series resistance (RS). Also the values of the barrier height obtained from the C–V measurements (Φb(CV)) of the MS and MIS was 0.863±0.034 eV and 1.187±0.093 eV, at 1 MHz, respectively.Distributions of the interface state density (Dit) of the MS and MIS devices were derivate from I–V and C–V measurements. Our results indicates that the Au/MB/n–GaAs device had lower interface state density values than the Au/GaAs device. Also non-saturated reverse bias current investigated by the using a Pole-Frenkel emission model. Furthermore, the optical and morphological properties of MB layer were investigated by the Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and UV-vis Spectrophotometer (UV-vis).Finally, we showed that, increasing Φb and decreasing Dit and improving electrical parameters of MIS devices indicates that, thin MB interface layer could prefer for modification of Au/n–GaAs devices.

Temperature-dependent electrical characteristics of Alq3/p-Si heterojunction

Al/Alq3(organic materials)/p-Si device was fabricated by the use of spin coating technique, and it was investigated by using current-voltage measurement in a wide temperature range from 80 to 320 K with 20 K steps. Some device parameters such as ideality factor, barrier height and series resistance values were determined by the use of standard thermionic emission theory and Norde functions, and the values found were compared with other studies. It was seen that all parameters of fabricated device strongly depended on temperature changes. AFM and SEM images were taken for better understanding surface morphology, and addressed in detail. The results of experiments suggest that the fabricated device with Alq3 organic interfacial layer could be used effectively in the temperature-dependent device applications for developing electronic technology.

Modified Interface Properties of Au/n-type GaN Schottky Junction with a High-k Ba0.6Sr0.4TiO3 Insulating Layer

The interface properties of a Au/n-GaN Schottky junction (SJ) were modified by placing a high-k barium strontium titanate (Ba0.6Sr0.4TiO3) insulating layer between the Au and n-GaN semiconductor. The surface morphology, chemical composition, and electrical properties of Au/Ba0.6Sr0.4TiO3 (BST)/n-GaN metal/insulator/semiconductor (MIS) junctions were explored by atomic force microscopy, energy-dispersive x-ray spectroscopy, current–voltage (I–V) and capacitance–voltage (C–V) techniques. The electrical results of the MIS junction are correlated with the SJ and discussed further. The MIS junction exhibited an exquisite rectifying nature compared to the SJ. An average barrier height (BH) and ideality factors were extracted to be 0.77 eV, 1.62 eV and 0.92 eV, 1.95 for the SJ and MIS junction, respectively. The barrier was raised by 150 meV for the MIS junction compared to the MS junction, implying that the BH was effectively altered by the BST insulating layer. The BH values extracted by I–V, Cheung’s and Norde functions were nearly equal to one another, indicating that the techniques applied here were dependable and suitable. The frequency-dependent properties of the SJ and MIS junction were explored and discussed. It was found that the interface state density of the MIS junction was smaller than the SJ. This implies that the BST layer plays an imperative role in the decreased NSS. Poole–Frenkel emission was the prevailed current conduction mechanism in the reverse-bias of both the SJ and MIS junction.

Forward and reverse bias current–voltage (I–V) characteristics in the metal–ferroelectric–semiconductor (Au/SrTiO3/n-Si) structures at room temperature

The main electrical parameters of fabricated Au/SrTiO3/n-Si (MFS) structures have been investigated by using various methods. The values of ideality factor (n) and zero-bias barrier height (ΦB0) are calculated from the forward bias current–voltage (IF–VF) data as 0.60, and 0.48 eV from thermionic theory (TE) and Cheung functions, respectively. The value of Rs is also obtained from the Norde function and Cheung functions as 87.83 and 137.57 Ω, respectively. The discrepancy between these results can be attributed to the calculated method and the measured voltage range. Besides, the energy density distribution profile of interface state (Nss) was obtained from the (IF–VF) data by taking into account voltage dependent barrier height (BH), n and without Rs. On the other hand, the possible current conduction mechanism (CCM) are determined by utilizing the In(IF) versus In(VF) and In(IR) versus VR1/2 plots. The double logarithmic IF–VF plot shows three linear regions which are corresponding to low, moderate and high bias voltages with different slopes (m) as 2.40, 1.96 and 1.27 respectively. While the first region space charge limited current (SCLC) is dominated, the other two regions ohmic behavior is dominated. The field-lowering coefficient (β) was also obtained from the slope of In(IR)–V1/2 plot as 4.40 $$\times$$ 10−6 eV−1 m1/2 V1/2. This value of β is close to theoretical value of Poole–Frenkel emission (PFE) rather than Schottky emission (SE) mechanism.

The structural and electrical characterization of Al/GO-SiO2/p-Si photodiode

GO-SiO2 composite structures were synthesized chemically and characterized by FTIR, XRD, TGA and SEM. The characterization results highlighted that the composite of the GO-SiO2 was obtained successfully and can be thought as interfacial layer between the metal and semiconductor. For that reason, the GO-SiO2 composites were inserted between Al metal and p-type Si semiconductor by spin coating technique, and Al/GO-SiO2/p-type Si device was obtained by aid of thermal evaporation. The obtained device was tested with I-V measurements for various illumination conditions. Ideality factor, barrier height and series resistance values were determined according to thermionic emission theory, Cheung and Norde functions. In addition, we studied transient photocurrent properties of the device. The results confirm that the device can be used as photodiode in the industrial applications as having good photostability and photoresponsivity.