Norde Method Research Articles

Electrical and photoresponse properties of CoSO4-PVP interlayer based MPS diodes

The cobalt sulfate-polyvinylpyrrolidone (CoSO4-PVP) solution was deposited on n-Si crystal by using spin-coated method. The electrical and photoresponse properties of Au/(CoSO4-PVP)/n-Si MPS diode were investigated both in the dark and under illumination (100 mW/cm2) level. MPS-type diode exhibits good rectifying behavior in dark condition. The measured reverse current under illumination was found to be higher than dark condition. The MPS diode has also a good response to the illumination and photosensitivity value was found as 5.25 × 103 for 100 mW/cm2. The diode parameters such as n, Φb0 and Rs were extracted based on both the thermionic-emission (TE) and Norde method. The current conduction mechanisms of the MPS diode were also analyzed by forward ln(IF)-ln(VF) and reverse ln(IR)-VR1/2 plots. Moreover, both the voltage dependence of C and G characteristics were investigated under 1 MHz. The other electrical parameters such as V0, VD, ND, EF, WD and ΦB were extracted from the C−2–V characteristics. Besides, the voltage dependence profile of the Nss was extracted by using dark-illumination capacitance (Cdark-Cill) measurements at a frequency of 1 MHz. The results suggest that the prepared Au/(CoSO4-PVP)/n-Si MPS diode can be used in optoelectronic device applications.

The evaluation of the current–voltage and capacitance–voltage-frequency measurements of Yb/p-Si Schottky diodes with a high zero-bias barrier height

The rare-earth metal Yb (Ytterbium) which has a very low work function of 2.60 eV has been shown to high quality Schottky contacts to p-Si. Two distinct linear regions in the semi-logarithmic current density–voltage plot are observed for Yb/p-Si Schottky diodes. From the linear regions, the very high zero-bias barrier height values are determined as 0.83 and 0.88 eV. The value of rectification ratio is in order of ~ 106 which is close to the commercial Schottky diodes. From Cheung functions, the value of series resistance is found to be 12.60 Ω. Furthermore, the important contact parameters of the diodes are calculated by using modified Norde method. The contact parameters obtained from reverse bias capacitance–voltage-frequency measurements do not show an important dependence on frequency. The calculated values of acceptor concentration are in close agreement with the value of doping concentration of the p-Si wafer used in this study.

Effect of Zinc Oxide (ZnO) Nanoparticles on Interfacial Barrier Height and Band Bending of Phenosafranin (PSF) Dye-Based Organic Device

In this work, the interfacial barrier height and formation of band bending are studied in a phenosafranin (PSF) dye-based organic device and the effect of zinc oxide nanoparticles on both of these device parameters is estimated. The results show that interfacial band bending influences the barrier height at the metal–organic semiconductor contact. Indium tin oxide (ITO)-coated glass and aluminium are used as front electrode and back electrode, respectively, in the device. Analysis of the current–voltage (I–V) characteristics of the device show that the barrier height is reduced from 0.81 eV to 0.67 eV in the presence of ZnO nanoparticles. The barrier height is also calculated by using the Norde method, which shows a reduction from 0.83 eV to 0.69 eV in the presence of ZnO nanoparticles. Thus the results obtained using the two methods are consistent. The presence of ZnO nanoparticles also reduces the band bending from 0.218 eV to 0.183 eV at the metal—organic dye interface. As both parameters are reduced due to the incorporation of ZnO nanoparticles, it can be concluded that the charge injection process at the interface of the metal–organic layer is improved. The improvement of the charge injection process also results in lowering the threshold voltage of the organic device from 4 V to 3.5 V.

Electrical characterization of silicon nitride interlayer-based MIS diode

In this study, silicon nitride (Si3N4) thin film on p-type GaAs wafer was deposited by RF magnetron sputtering. The surface morphology of Si3N4/GaAs structure was analyzed by atomic force microscopy (AFM). The electrical characteristics of the fabricated Au/Si3N4/p-GaAs metal–insulator-semiconductor (MIS) diode were investigated by using current–voltage (I–V) measurements at room temperature. The electronic parameters such as ideality factor (n) and barrier height (Φbo) of the MIS diode were derived using thermionic emission (TE). The Φbo was also extracted from Norde method. The barrier height values obtained from both TE and Norde were found to be in harmony with each other. The interface state density (Nss) and series resistance (Rs) parameters of the MIS diode were determined from the measured I–V data. In addition, the dominant current conduction mechanisms of the MIS diode were also investigated by forward bias ln(IF) − ln(VF) and reverse bias ln(IR) − VR0.5 plot. At high forward bias, the current conduction was associated with the space charge limited current (SCLC). At reverse bias region, the current conduction was associated with the Schottky emission (SE).

A growth of A–Z phthalocyanine layers onto Si by thermal evaporation process to achieve organic heterojunction diodes

Thermally evaporated organic heterojunction (OHJ) diodes based on A–Z phthalocyanine (ZnPc/pSi and AlPc/Si) are investigated. Here, we study the electronic parameters of ZnPc/pSi and AlPc/Si organic heterojunction diodes. Such organic heterojunctions are produced by thermal evaporation process in vacuum at very low pressure. For this purpose, the current–voltage (I–V) characteristics at room temperature under dark conditions for the organic aluminum and zinc (A–Z) phthalocyanine materials are measured. Firstly, the electronic parameters of the organic heterojunctions including ideality factor n, barrier height (Φb), series resistance (RS) are extracted via Cheung and Norde methods respectively. A high rectification ratio (RR) in order of 2 × 104 is recorded for ZnPc/p-Si contacts. Non-ideal behavior of AZPc OHJ is revealed n ∼ 2.4, series resistance and barrier height are of 2 kΩ and 0.4 eV. Secondly, the conduction mechanism of both AlPc/Si and ZnPc/Si contacts are investigated. SCLC is the dominated conduction mechanism throughout the OHJ device.

The comparison of Co/hematoxylin/n-Si and Co/hematoxylin/p-Si devices as rectifier for a wide range temperature

We employed hematoxylin as interfacial layer between the n- and p-type silicon substrate and cobalt (Co) metallic contact to obtain and compare Co/hematoxylin/n-Si and Co/hematoxylin/p-Si devices for a wide range temperature via current-voltage (I–V) characteristics. Furthermore, we studied structural and morphological properties of the hematoxylin thin film by x-ray diffractometer (XRD) and scanning electron microscope (SEM). The temperature range was changed from 100 K to 460 K via 20 K interval for I–V measurements. The Co/hematoxylin/n-Si and Co/hematoxylin/p-Si devices exhibited excellent rectifying behaviors for low temperatures, but rectifying ratio (RR) values decreased with increasing temperature at ±1 V bias. In addition, the devices showed thermal sensor or detector behavior because current values increased with increasing temperature at reverse biases. The Co/hematoxylin/p-Si device has better stability than Co/hematoxylin/n-Si device at reverse biases for the same temperature values according to stop leakage current with increasing voltage. In addition, the diode parameters such as barrier height, ideality factor and series resistance as well as interface states density were extracted from the I–V measurements and compared in details for various techniques such as thermionic emission theory, Norde and Cheung methods. The diode parameters of the both devices were affected from the temperature changes. The Co/hematoxylin/n-Si and Co/hematoxylin/p-Si devices are good candidate for rectifying and thermal sensing applications.

Current-transport mechanisms in the Au/GaSe:Nd Schottky contact

Structural and electrical features of p-type neodymium-doped GaSe single crystal (0.1 at.% Nd) grown by modified Bridgman technique was investigated through X-ray diffraction (XRD) and current–voltage (I–V) measurements. The XRD spectrum reveals that GaSe:Nd single crystal investigated has hexagonal structure (a = 3.750 A, c = 15.950 A and z = 4, P63/mmc space group) with preferred orientation along (004). Ohmic contact was realized by evaporating indium (In) on one surface of the GaSe:Nd single crystal at 10–6 Torr while Shottky contact was obtained by evaporating twelve Au dot contacts with 7.85 × 10–3 cm2 area on the other surface of the crystal. The I–V characteristics of Au/GaSe:Nd/In Schottky contact was analysed in the 100–360 K temperature range. The main Schottky diode parameters such as ideality factor, barrier height and the series resistance values were determined as a function of temperature using conventional I–V method and Norde method. The ideality factor n of the Au/GaSe:Nd/In Schottky contact was observed to decrease while the barrier height $$\Phi_{\rm b}$$ increased with increasing temperature. Temperature dependence of the diode parameters were attributed to the existence of barrier height inhomogeneity by assuming a Gaussian distribution of Au/GaSe:Nd/In Schottky contact.

Analysis of Double Gaussian Distribution at the Interface of Ni/Ta2O5/P-Si Schottky Barrier Diodes Using Temperature Dependent Current-Voltage (I-V) Measurements

The electrical properties have been investigated for Ni/Ta2O5/p-Si Metal/insulator/semiconductor SBD in the temperature regime 175–400 K. The electrical parameters were analyzed using current-voltage characteristics as a function of operating temperature. It is observed that the Schottky barrier height increased whereas ideality factor and series resistance decreased with increasing the operating temperature. The characteristic temperature (To) value calculated from Norde and Cheung methods was compared. This analysis showed that To value extracted from both the techniques are in close agreement with each other. Experimental results revealed that the thermal coefficient was −4.5 mV/K. The Gaussian distribution of the barrier height was estimated from the plot of zero-bias barrier height (Φbo) versus 1/2kT plot and the estimated value of (Φbo) of 0.92 eV and 0.79 eV with standard deviation (σ0) of 0.023 V and 0.014 V, respectively. The mean BH and the Richardson constant values were determined using ln (Io/T2)-q2 $$ {\sigma}_0^2 $$ /2(kT)2 versus 1000/T plot and were 0.89 eV and 0.76 eV and 30.03 and 26.85 A/cm−2 K−2, respectively. In addition to the thermionic emission process, two more conduction mechanisms such as Poole-Frenkel emission in the temperature regime 175–275 K and Schottky emission dominant beyond 300 K temperature were noticed.

A Temperature Sensor Based on Al/p-Si/CuCdO2/Al Diode for Low Temperature Applications

CuCdO2 delafossite oxide film as an interface layer was coated by sol–gel spin coating on p-Si substrate, and thus an Al/p-Si/CuCdO2/Al diode was fabricated. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) was used to obtain an image of the CuCdO2 oxide film. The temperature-dependent behavior of the diode was studied by current–voltage (I–V) and capacitance/conductance–voltage (C/G–V) measurements over the 100–400 K temperature range. It is observed that the ideality factor (n) decreases and zero-bias barrier height (Φb0) increases with an increase in temperature. This abnormal behavior of n and Φb0 is attributed to barrier inhomogeneities by assuming Gaussian distribution (GD) at the metal–semiconductor interface. For each temperature, the barrier height values obtained from both the conventional I–V and Norde method show good agreement with each other. The I–V–T characteristics have shown the GD, giving a mean barrier height ($$ {\bar{\Phi }}_{b0} $$) of 1.04 eV and a standard deviation (σs) of 0.12 V. A modified Richardson plot of [ln(I0/T2) − q2σs2/2k2T2 versus q/kT] yields $$ {\bar{\Phi }}_{b0} $$ and A* as 1.06 eV and 31.21 A cm−2 K−2 (indicating an agreement with the theoretical value of 32 A cm−2 K−2), showing the promise of CuCdO2/Si as temperature sensing with a Schottky junction. In addition, C–V and G–V measurements show that the C value decreases and the G value increases as the frequency increases, depending on a continuous distribution of interface states. Also, the capacitance and the conductance values decrease with increasing temperature. The results suggest that Al/p-Si/CuCdO2/Al diode can be used for temperature sensing applications.

Effect of back electrode on trap energy and interfacial barrier height of crystal violet dye-based organic device

In this work, we have studied the effect of aluminium-coated mylar (Al–M) sheet-based back electrode and aluminium (Al)-coated back electrode on trap energy ( $$E_{\mathrm {t}})$$ and barrier height ( $$\phi _{\mathrm {b}})$$ of crystal violet (CV) dye-based organic device. Two devices have been prepared using two different back electrodes. In both the devices, ITO-coated glass is used as front electrode. Both the organic devices have been prepared by using spin-coating techniques. We have measured the steady state current–voltage (I–V) characteristics of these devices to estimate the trap energy ( $$E_{\mathrm {t}})$$ and barrier height ( $$\phi _{\mathrm {b}})$$ of the devices. Because of the insertion of a reflecting back electrode, the charge carriers are confined in the active layer, which reduces the $$E_{\mathrm {t}}$$ from 0.044 to 0.034 eV and $$\phi _{\mathrm {b}}$$ is reduced from 0.80 to 0.77 eV. The barrier height is also estimated by using another alternative method, which is known as Norde method. By using Norde method, $$\phi _{\mathrm {b}}$$ is estimated, which reduces from 0.83 to 0.79 eV in the presence of reflecting back electrode. Both the methods show good consistency with each other. The reductions of these parameters indicate the enhancement of charge injection through the metal-organic dye interface. With the use of polished back electrode in the CV dye-based organic device, it is possible to modify the barrier height and trap energy and thereby modifies the conductivity.

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.

Sr-doped yttrium nickel oxide-based photodetectors

In this research, Sr-doped yttrium nickel oxide-based photodetectors have been fabricated. The electrical properties of diodes have been analyzed by using Cheung and Norde methods. The ideality factors, barrier heights, and series resistances of diodes have been calculated under visible light at different irradiation intensities. In addition, the photoresponse behavior of photodetectors was investigated under visible light at different irradiation intensities. The highest responsivity (R) and detectivity (D*) were calculated as 25.34 mA/W and 7 × 84 1011 Jones, respectively. These results suggest that the photodetectors can be used optoelectronic device applications.

Temperature dependent characteristics of Ni/Au vertical Schottky diode based on mechanically exfoliated beta-Ga<sub>2</sub>O<sub>3</sub> single crystal

In this paper, a Ni/Au vertical structure Schottky diode based on mechanically exfoliated β-Ga<sub>2</sub>O<sub>3</sub> is fabricated. The temperature dependent characteristics of <i>I</i>-<i>V</i> curves are measured. The device shows a good rectifying behavior. As the temperature increases from 300 K to 473 K, the barrier height increases from 1.08 eV to 1.35 eV, and the ideal factor decreases from 1.32 to 1.19. Both of them show strong temperature dependence, which indicates that the Schottky barrier of the device is inhomogeneous. The device has a double exponential forward I-V characteristic curve, which may be related to crystal defects, surface states, surface energy band bending and the effect of mechanical exfoliation from the crystal surface. Through Cheung's method and Norde's method, the series resistances and barrier heights of the device at different temperatures are extracted. It is found that the parameters extracted by the Norde's method are in good agreement with the values obtained from the forward <i>I</i>-<i>V</i> curve. The series resistance decreases with temperature increasing, which is mainly caused by the increase of the concentration of thermally excited carriers. In this paper, the temperature characteristics of the device are modified by the Gauss distribution of the barrier height. The corrected barrier height is 1.54 eV and Richardson's constant is 26.35 A·cm<sup>–2</sup>·K<sup>–2</sup>, which is closer to the theoretical value. It shows that the <i>I</i>-<i>V</i> temperature characteristics of Au/Ni/β-Ga<sub>2</sub>O<sub>3</sub> Schottky diodes can be described by the thermionic emission model of the Gauss distribution barrier height accurately. There are a lot of surface states on the surface of Ga<sub>2</sub>O<sub>3</sub> single crystal obtained by Mechanical exfoliation, which has a great influence on the Schottky contact of the device and may lead to the inhomogeneity of Schottky barriers. At the same time, due to mechanical exploiation, the surface of gallium oxide single crystal material is not completely continuous, and the single crystal surface has layered or island structure. This will also cause the inhomogeneous Schottky barrier height. Considering the influence of inhomogeneous barrier on Schottky diode, the method of measuring the temperature characteristics is more suitable to extracting the electrical parameters of β-Ga<sub>2</sub>O<sub>3</sub> Schottky diodes than the method of fitting <i>I</i>-<i>V</i> forward curve by TE model.

Study on the Effect of Zinc Oxide Nanoparticles on Injection Barrier Height of Crystal Violet Dye Based Organic Device

Organic devices have achieved substantial progress due to its flexibility, cost effectiveness, simple processing and wide customizability. But there are certain limitations of these devices. One of the main limitations is the lower charge injection from metal electrodes to the organic layer which affects the performance of these devices. The charge injection process is strongly dependent on the injection barrier height at metal- organic layer interface. Due to high barrier height at metal – organic layer interface, the charge injection is reduced at the interface. Attempts need to be made to reduce the injection barrier height at metal – organic layer interface to improve the charge injection process. In the present work, we have studied the injection barrier height of Indium tin oxide coated glass/Crystal violet dye/Aluminium based organic device and subsequently we have also observed the effect of zinc oxide nanoparticles on injection barrier height of this device. Indium tin oxide coated glass and aluminium are used as front electrode and back electrode respectively to form this device. The device has been prepared with and without zinc oxide nanoparticles by using spin coating technique. We have analyzed the steady state current-voltage characteristics of the device to determine the barrier height of the device. Barrier height is reduced from 0.87 eV to 0.78 eV in the presence of zinc oxide nanoparticles. The barrier height is also estimated by using another alternative method which is known as Norde method. By using Norde method, barrier height is measured which reduces from 0.83 eV to 0.77 eV in presence of zinc oxide nanoparticles. Both the methods show good consistency with each other. Reduction of the injection barrier height in presence of zinc oxide nanoparticles indicates better charge injection through the metal - organic dye interface. The higher electron mobility of zinc oxide nanoparticles facilitates efficient charge injection at the interface. Thus, this work will be informative to study the effect of zinc oxide nanoparticles on injection barrier height as it reduces the barrier height to improve the charge flow at metal – organic dye interface.

Exploration of organic additives-assisted vanadium pentoxide (V2O5) nanoparticles for Cu/n-V2O5/p-Si Schottky diode applications

The organic additives-assisted vanadium pentoxide (OA:V2O5) nanoparticles (NPs) were prepared by a facile co-precipitation method and their structural, optical, and electrical properties have been analyzed. The orthorhombic crystal structure was observed in the X-ray diffraction pattern of pure vanadium pentoxide (V2O5) NPs. The XRD patterns of OA: V2O5 NPs reveals that the crystallite size of the V2O5 NPs reduced without any change in the crystal structure. The SEM images showed that organic additives strongly influence on the surface morphology of the V2O5 NPs. The TEM analysis revealed that the acid-treated V2O5 NPs are relatively smaller in size compared to without acid-treated V2O5 NPs. From the optical measurements, an increase in optical band gap was observed for OA:V2O5 NPs. The dc electrical analysis revealed that the increased dc electrical conductivity is due to the incorporation of various organic additives (OA) in the V2O5 NPs. The electrical parameters such as ideality factor (n), barrier height (ФB), series resistance (Rs), and interface properties have been analyzed for the Cu/n-V2O5/p-Si Schottky diodes (SBDs) by the J–V, Cheung’s and Norde method. The barrier height value is increased for Cu/OA:V2O5/p-Si SBDs.

Electrical Characterization of RF Reactive Sputtered p–Mg-InxGa1−xN/n–Si Hetero-Junction Diodes without Using Buffer Layer

The modeling of p–InxGa1−xN/n–Si hetero junction diodes without using the buffer layer were investigated with the “top-top” electrode. The p–Mg-GaN and p–Mg-In0.05Ga0.95N were deposited directly on the n–Si (100) wafer by the RF reactive sputtering at 400 °C with single cermet targets. Al and Pt with the square size of 1 mm2 were used for electrodes of p–InxGa1−xN/n–Si diodes. Both devices had been designed to prove the p-type performance of 10% Mg-doped in GaN and InGaN films. By Hall measurement at the room temperature (RT), the holes concentration and mobility were determined to be Np = 3.45 × 1016 cm−3 and µ = 145 cm2/V·s for p–GaN film, Np = 2.53 × 1017 cm−3, and µ = 45 cm2/V·s for p–InGaN film. By the I–V measurement at RT, the leakage currents at −5 V and turn-on voltages were found to be 9.31 × 10−7 A and 2.4 V for p–GaN/n–Si and 3.38 × 10−6 A and 1.5 V for p–InGaN/n–Si diode. The current densities at the forward bias of 20 V were 0.421 and 0.814 A·cm−2 for p–GaN/n–Si and p–InGaN/n–Si devices. The electrical properties were measured at the temperature range of 25 to 150 °C. By calculating based on the TE mode, Cheungs’ and Norde methods, and other parameters of diodes were also determined and compared.

FABRICATION of n-ZnO:Mn/p-Si HETEROJUNCTION DIODES and ITS I-V, C-V CHARACTERISTICS

To investigate the effects of Mn dopant on n-ZnO/p-Si device performance, ZnO films were produced in different Mn dopant by the sol gel spin coating method. Morphological properties of the films were studied by emission scanning electron microscopy (FESEM). Then, the n-ZnO:Mn/p-Si heterojunction diodes were fabricated. The diode parameters were determined by current-voltage (I-V) measurements. The values of the diodes were found to be 8.38, 6.84 and 3.87, respectively, for the diodes produced using undoped, 1% Mn doped and 3% Mn doped ZnO films. At the same time, electrical parameters were determined to compare by using Cheung and Norde methods. According to the evaluation of values obtained by different methods, an improvement on the rectifying properties of the ZnO diode with Mn dopant has been observed. In the continuation of the study, the photovoltaic properties of the heterojunction diodes have been studied. The results obtained at different illumination intensities showed that the diodes are sensitive to light. Capacitance-voltage (C-V) measurements of the fabricated diodes are also investigated in detail.

Comparison of electrical properties of MS and MPS type diode in respect of (In2O3-PVP) interlayer

In this study, the electronic properties of Au/n-Si (MS) and Au/(In2O3-PVP)/n-Si (MPS) diode have been investigated to see the effects of an organic (In2O3-PVP) interlayer by utilizing voltage-dependent current (I) and capacitance (C) measurements. The organic indium oxide (In2O3) nanostructures were characterized by XRD, SEM and UV–Vis spectrophotometer techniques. The rectifying ratio (RR) of the fabricated MS and MPS diode at ± 3 V was found as 1.89 × 103 and 6.18 × 103, respectively. The electronic parameters for instance the ideality factor (n) and barrier height (ΦBo) of MS and MPS diode were found as 1.94 and 2.20, and 0.73 eV and 0.76 eV, respectively. Additionally, series resistance (Rs), n, and ΦBo values were calculated by using Cheung's functions as second way to see the used calculation method and voltage effects on them. Therefore, the Rs and ΦBo values were determined from both the Norde method and C–V characteristics.

Improved barrier parameters and working stability of Au/p-GO/n-lnP/Au–Ge Schottky barrier diode with GO interlayer showing resistive switching effect

In this study, Au/p-GO/n-lnP/Au–Ge device structure for possible micro- and opto-electronic applications has been investigated. Firstly, the graphene oxide (GO) interlayer has been characterized before device fabrication. The GO interlayer has band gap energy of 2.4 eV and large contact area. In the Raman spectrum, ID/IG ratio was determined as 0.78. According to the Thermionic, Norde and Cheung methods, ideality factor, Schottky barrier height, series resistance and distribution of interface states have been investigated for the devices. The presence of GO interlayer has caused to both the barrier height increased from 0.44 to 0.71 eV and the significant increase in rectification ratio from 102 to 105 at ±1 V. Additionally, the ideality factor has improved from 1.32 to 1.23 at 300 K. The device working stability at high temperatures (400 K) has been observed in the Au/p-GO/n-lnP/Au–Ge device. Furthermore, the resistive switching effect of the GO interlayer has been observed as temperature-dependent metallic character of series resistance in high voltage region.

Temperature dependent current-voltage characteristics of Al/TiO2/n-Si and Al/Cu:TiO2/n-Si devices

We fabricated undoped and Cu doped TiO2 thin films by spin coating technique and employed the films as interfacial oxide layer between the Al and n-type Si to investigate the effect of temperature on the Al/TiO2/n-Si and Al/Cu:TiO2/n-Si devices. For that aim, the I–V measurements were performed in the range of 50 K–400 K by 50 K interval. The devices exhibited good rectifying behavior and thermal response in a wide range temperature. Ideality factor, barrier height and series resistance were calculated from I–V measurements for various temperatures by thermionic emission theory, Norde and Cheung methods and discussed in the details. The obtained results revealed that the device parameters are a strong function of the temperature. The interface states (Nss) were affected by the changing of the temperatures. The Al/TiO2/n-Si and Al/Cu:TiO2/n-Si devices can be performed for wide range temperatures in various technological applications.