Diode Parameters Research Articles

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.

An atomic filter laser with a compact Voigt anomalous dispersion optical filter

The study of atomic physics has been greatly influenced by the development of high-stability diode lasers whose output corresponds to the atomic transition. Recently, an atomic filter laser “Faraday laser” shines on stage, owing to its great robustness to the fluctuation of the diode parameters and potentially higher tolerance to vibration. However, cost reduction and portability require the Faraday laser to have a more compact structure. Here, we report on the development of a promising atomic filter laser—a “Voigt laser”—using a Voigt anomalous dispersion optical filter (VADOF) as the frequency-selective element, which has a structural advantage in miniaturization. The influencing factors toward the VADOF are investigated in detail to produce a parameter set for the best performance of a Voigt laser. In this case, the Voigt laser has great robustness to the fluctuation in the diode current and temperature, where the wavelength fluctuation is ±0.5 pm with the variation of the diode parameters (diode current: 73–150 mA and diode temperature: 12–30 °C). In addition, the wavelength of the Voigt laser fluctuates about ± 0.5 pm for 48-h free-running operation and shows excellent reproducibility without manual adjustment. The laser system developed here provides a stable and reliable laser source for substantially improving existing technologies such as the atomic clock, electromagnetically induced transparency, and laser cooling of atoms.

Comparison of Al/TiO2/p-Si and Al/ZnO/p-Si photodetectors

The importance of the photodetectors has grown due to their potential in the automation system and optical communications. We fabricated Al/TiO2/p-Si and Al/ZnO/p-Si Schottky-type photodetectors. TiO2 and ZnO interlayers were grown by atomic layer deposition (ALD). The photodetection properties of these devices were studied and compared by I–V and I-t measurements for various light power densities and various wavelengths. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectra were employed to determine morphological and elemental analysis of the TiO2 and ZnO interlayers. While the SEM images showed smooth surfaces, EDX spectra approved successful synthesis of the TiO2 and ZnO interlayers with good stoichiometry. The diode parameters such as ideality factor, series resistance and barrier height values were calculated and compared in detail. The responsivity and detectivity of the fabricated photodetectors were determined as a function of illumination power density and wavelength. The responsivity values of the Al/TiO2/p-Si and Al/ZnO/p-Si photodetectors were determined as 0.02 and 0.76 A/W, respectively. Both photodetectors exhibited good performance for visible light. However, Al/ZnO/p-Si photodetector reached 173.08% external quantum efficiency (EQE) for 550 nm. According to results, Al/ZnO/p-Si photodetector exhibited better detection performance than Al/TiO2/p-Si.

Application of RSAPSO Hybrid Optimizer for Parameter Extraction of Solar PV Cell Models under Temperature Variations

Accurate modeling of photovoltaic (PV) modules/cells is crucial for evaluating the efficiency of solar PV systems. However, the lack of specific parameters of solar cells, which are not included in the manufacturer’s datasheet, often results in flawed cell modeling. Quick and convenient parameter extraction techniques are required to overcome this challenge and create a robust solar PV cell model. These models are useful in optimization, simulation, and enhanced energy harvesting from PV-based renewable energy systems. This paper uses a recent optimizer called Rat Search Algorithm Particle Swarm Optimization (RSAPSO), for extracting the parameters of single diode and double diode models of PV cells. RSAPSO combines the exploration and exploitation advantages of both algorithms. The RSAPSO's parameter optimization results were compared against five other techniques, and the superiority of the suggested algorithm was confirmed through ranking tests, statistical error analyses, and temperature variation sensitivity analyses.

Machine learning models for efficient characterization of Schottky barrier photodiode internal parameters

We propose ANN-based models to analyze and extract the internal parameters of a Schottky photodiode (SPD) without presenting them with any knowledge of the highly nonlinear thermionic emission (TE) expression of the device current. We train, evaluate and demonstrate the ML models on thirty-six private datasets from three previously published devices, which denote current responses under illumination and ambient temperature of graphene oxide (GO) doped p-Si Schottky barrier diodes (SBDs). The GO doping levels are 0%, 1%, 3%, 5%, and 10%. The illumination ranged from dark (0 mW/cm2) to 30 mW/cm2. The predictions are then made completely at the intensity of 60 mW/cm2. For each diode, some values of the barrier height (phi ), ideality factor (n), and series resistance (R_s) independently calculated using the Cheung–Cheung method were included in the training dataset. The predictions are done at unspecified intensities on the model development data at 80 and 100 mW/cm2, and on external data at 5% and 20% GO doping which were not part of the development dataset. The ANN achieved a mean square error and mean absolute error score below 0.003 across all datasets. This demonstrates the effective learning capabilities of the ANN models in accurately capturing the photo responses of the photodiodes and accurately predicting the internal parameters of the Schottky Barrier Diodes (SBDs), all without relying on an inherent understanding of the thermionic emission (TE) equation for SBDs. The ANN models achieved high accuracy in this process. The proposed ML models can significantly reduce analysis time in device development cycles and can be applied to other datasets in various fields.

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.

MODERNIZATION OF THE HELIUM ION ACCELERATOR MICROWAVE POWER SUPPLY SYSTEM

The high-voltage rectifier modernization, which is part of helium accelerator (PSS-4) high-frequency system, is described. The rectifier supplies the pulse modulator with direct current energy. The valves of the modulator used are mercury thyratrons. Modernization involves replacing thyratrons with semiconductor diodes. In the article, a comparative analysis of the parameters of thyratrons and diodes, which are supposed to be replaced by thyratrons, is carried out, and the expediency of such a replacement is substantiated.

Investigating charge transportation and photo-responsive outcome of a Schottky diode fabricated by 2-amino terephthalic acid directed supramolecular Mn(II)-metallogel

This study investigates a supramolecular metallogel formed using an ultrasonication technique and employing manganese acetate tetrahydrate as a metal salt, 2-amino terephthalic acid (ATA) as an organic gelator, and N,N′-dimethyl formamide and dimethyl sulfoxide as mixed solvents. The mechanical toughness and viscoelastic parameters of the metallogel material were well demonstrated by rheology-based experimental values of storage and loss moduli with rotational frequency, shear strain, and shear stress of the Mn(II)-metallogel (Mn-ATA). The microstructural analysis along with chemical composition were shown using field emission scanning electron microscopy and energy dispersive X-ray analysis-based elemental research. Analysis of the infrared spectrum aided in determining how Mn-ATA was formed. Electrospray ionization mass investigation of Mn-ATA demonstrated the existence of several metallogel components and their engagement in producing the metallogel structure. Different diode parameters (i.e. photosensitivity, photoconductivity sensitivity, responsivity, specific detectivity, ideality factor, barrier height, and series resistance were measured, revealing the semiconducting property of the metallogel. The current–voltage characteristics of a Mn-ATA-based thin-film type metal–semiconductor junction device demonstrated non-linear rectifying behavior, indicating Schottky diode behavior with dominating electronic-charge transport features. The device displayed an improved rectifying property under illumination, which also implied higher conductivity. The device's measured conductivity in the low-voltage domain (equivalent to ohmic behavior) was 1.03 × 10−5 and 4.12 × 10−5 Sm−1 under darkness and illumination, respectively, implying photo-responsive behavior.

In-depth opto-electrical analysis of Ni:CdS film towards the performance as Ag/Ni:CdS/FTO Schottky diode

Nickel doped cadmium sulfide (Ni:CdS) thin films are deposited onto glass and FTO substrate using spray pyrolysis technique. The effect of annealing temperature on the thin films and its morphological, microstructural, optical dispersion, linear-nonlinear and electrical, properties are extensively investigated by using various techniques such as field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM), X-ray diffraction (XRD) and ultraviolet visible (UV-VIS) diffuse reflectance spectroscopy. Morphological studies revealed that doped thin films surface is almost homogeneous and well-covered. Peaks associated with Ni, Cd and S elements are present in EDS analysis, which confirm the composition of the films. The energy band calculation using the Tauc plot from the recorded absorption spectra reveals the decrement in the energy gap from 3.75 eV to 3.61 eV and the refractive index is in the range of 2.57–2.62. The effect of annealing temperature on complex dielectric constant are also analyzed. Moreover, the dispersion of refractive index is calculated in terms of Wemple-DiDomenico approach. Third order susceptibility and nonlinear refractive index are calculated of Ni:CdS films. The designed Ag/Ni:CdS/FTO Schottky diode is tested under illumination conditions, and the empirical diode parameters, viz. ideality factor, barrier height, series resistance etc. are influenced by annealing temperature.

Characterisation of interface states of Al/p-Si Schottky diode by current–voltage and capacitance–voltage–frequency measurements

In this study, the fabricated Al/p-Si Schottky diode is characterised at room temperature using current–voltage (I–V) and capacitance–voltage–frequency (C–V–f) techniques. The energy distribution profile of the diode’s interface state density is generated using different diode parameters. In the I–V measurements, the variation in energy, charge, and density of the interface states is described in terms of the applied forward bias with respect to the zero Schottky barrier height. The capacitance measurements, on the other hand, are used to address a long-standing low-voltage capacitance peak in terms of the distribution of interface state charge. In general, both techniques complement each other, indicating that the space charge region (SCR) starts to be varied at a voltage of − 0.66 V, after the compensation of interface states by majority carriers. The findings presented here are critical for current and future research on junction-based devices for a variety of applications in which the SCR and bulk material properties are examined solely from metal-semiconductor (m–s) interface states.

Improved design and development of an automated jet nebulizer spray pyrolysis system for Ag/Zn: CuO/Si structured diode application

Zinc-doped Copper oxide (Zn:CuO) thin films are deposited via well-designed automated jet nebulizer spray pyrolysis (JNSP) system for developing Ag/Zn:CuO/n-Si structured diode. The system is fitted with a microcontroller-based spray nozzle with an up/down movement to enable thin film deposition in an automated way. Zn:CuO thin films are deposited via an automated JNSP system with 1%, 3%, and 5% doping concentration. The characteristics studies and analysis of Zn:CuO thin films are studied. XRD examination showed that all of the Zn:CuO thin films have a monoclinic crystal structure. Surface morphological analysis of an automated Zn:CuO thin films showed spherical-shaped small grains. It is found that particles are closely packed and well covered. Additionally, elementary composition analysis (EDS) is carried through to finalize the ‘Cu’, ‘O’, and ‘Zn’ atoms in the deposited Zn:CuO materials. The least energy band gap of 1.90 eV and the highest conductivity of 3.67 x 10-8 S/cm is obtained for 3% Zn doped CuO. Based on the characteristics analysis and studies of automated Zn:CuO thin films, Ag/Zn:CuO/Si structured diode have been developed. Various diode parameters have been evaluated under light and dark conditions.

AgSbTe2 semi-nanocrystalline thin films as a multifunctional platform for optoelectronic and diode applications

The synthesis of the nanosized multifunctional thin film provides new solutions for many technological issues and consider a great step for miniaturized technology. Toward these goals, AgSbTe2 semi-nanocrystalline thin films of different thicknesses were synthesized by the thermal evaporation technique. The structural features were investigated by X-ray diffraction, and selected area electron diffraction (SAED) yielding a semi-nanocrystalline thin film of grain size ranging from 9.98 to 21.38 nm. The energy-dispersive X-ray spectroscopy (EDAX) verified the high purity and stoichiometry of the deposited films. For optoelectronic application, many optical parameters, including band gap (Eg), Urbach energy (Eu), Refractive index (n), dispersion energy (Ed), electronic polarizability (αe), and interband transition strength (JCV) were extensively discussed. The optical band gap reduced from 1.41 to 1.04 eV upon increasing the thickness from 150 to 550 nm. The temperature dependence of the electrical resistivity (ρ) of nanosized thin film was measured and the activation energy was estimated and it was found that the resistivity increased up to 450 K asserting the semiconductor behavior of the films. As for diode application, The Ag/2D-MoS2/p-AgSbTe2 (550 nm)/n-Si/Al heterostructure diode was constructed by thermal evaporation and all the diode parameters alongside conduction mechanism were studied in detail. AgSbTe2-based diode showed a low rectification ratio; however, the ideality factor (n) and zero bias barrier height (Φb) had optimal values of about 1.40 and 0.75 at room temperature, respectively.

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.

Modelling of photovoltaic cells using Boole’s rule-based multi-objective genetic algorithm implemented in Indoor hardware setup

Triple Diode Solar Cell Module (TDSCM) circuit with nine parameters for various environmental circumstances represents the behavior and practical performance of solar cell.The precise extraction of photovoltaic (PV) module parameters is essential for optimising the energy conversion efficiency of PV systems. Usually the equations describing solar panels are implicit in nature, and parameter extraction has been very complicated. The solar cell is mathematically modelled with nonlinear I-V (Current – Voltage) characteristics behavior, and it cannot be directly determined from the PV’s datasheet due to the lack of data offered by the PV manufacturers. On the basis of the technical datasheet of the photovoltaic module (PV), only four equations can be obtained in single diode, double diode, and triple diode parameters. To be implemented with fifth equation, many researchers have been done with multiple approximations and it becomes with low accuracy, complexity of computation, convergence problem. To resolve these issues, a new multi-objective optimization (GA) genetic algorithm method is prescribed to frame the fifth equation using the Boole rules implemented with the curved area concept. The proposed Boole’s rule based model offers superior non-linearity performance and high precision modelling, and the error shows a significant reduction when compared to the single and double diode approaches used in the existing approach. The effectiveness of the proposed I-V curve characteristics efficiency was improved by the implementation of the proposed Boole’s rule with RMSE error 0.000034.

Temperature dependency of electronic and optoelectronic performance of 2,4-Bis[4-(N,N-dibenzylamino)-2,6-dihydroxyphenyl]squaraine/n-Si organic/inorganic heterojunction for photovoltaic application

The potential of squaraine dyes in solar cells lies in their ability to strongly absorb in the visible and near-infrared regions, as well as their high molar absorptivity. Vacuum deposition was used to prepare a heterojunction (HJ) of 2,4-Bis[4-(N,N-dibenzylamino)-2,6 dihydroxyphenyl]squaraine dye (SQ) thermally deposited onto n-type Si wafer. The SQ film was analyzed using atomic force microscopy, which revealed an average grain size of 35 nm. X-ray diffraction procedure was applied to recognize the internal crystal structural properties of the SQ film deposited onto n-type Si wafer, showing that it has a nanostructure with a crystal size of 23 nm. The absorption study revealed that the SQ film has two band gaps, measuring 1.71 and 2.23 eV. The electronic properties of the SQ/n-Si HJ were analyzed under varying temperatures (298–378 K) in dark conditions. The current density-voltage (J-V) and capacitance-voltage (C–V) procedures were applied to extract the diode parameters of SQ/n-Si HJ, which displayed temperature-dependent behavior. The SQ/n-Si HJ exhibited photovoltage conductivity under light, allowing for the evaluation of photovoltaic parameters. At room temperature, 7.596 mA/cm2, 0.625 V, and 2.04% corresponding to photovoltaic parameters of SQ/n-Si HJ were obtained for short-circuit current (Jsc), open-circuit voltage (Voc) and power conversion efficiency (PCE%), respectively. However, it was observed that these photovoltaic parameters decreased as the temperature increased. These findings suggest that the SQ/n-Si HJ has the potential for utilization in photovoltaic devices.

Charge transport, photoresponse and impedance spectroscopy for Au/NiTPP/n-Si/Al diode

The current work was illustrated the impact of a thin film from Ni (II) Tetraphenylporphyrin (NiTPP) on the performance of the Au/n-Si Schottky. Structural and topographical properties of a NiTPP/n-Si thin film were examined using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The NiTPP/n-Si film was nanocrystalline, with an average crystallite size of approximately 33.87 nm and an average roughness of around 4.30 nm. The molecular structure and purity of NiTPP/n-Si were also confirmed using Raman spectra. Dark current-voltage (I-V) characteristics were used to determine and describe the diode parameters and conduction processes at forward bias as a function of temperature (300–390 K) for an Au/NiTPP/n-Si/Al diode. Photoresponse qualities of the diode were investigated under different illumination conditions. The reverse current of the diode grows as the light intensity increases. Impedance spectroscopy (IS) was performed at 0.025–1000 kHz. To assess the interface and recombination processes, the equivalent circuit model was thoroughly investigated. The findings demonstrate that the Au/NiTPP/n-Si/Al diode as a photodetector had significant potential for using in next-generation electrical devices.

Breaking Boundaries in LED Technology: Exploring the Revolutionary Diode Characteristics of Screen Printed (TiO2)1−x (CuO)x Thick Films

A thick TiO2-CuO composite film is deposited on a Si substrate by a low-cost screen printing method. Both anatase and CuO-doped TiO2 are characterized for diode applications. X-ray Diffraction (XRD) confirms that the composite film exists as an anatase phase of TiO2 and a monoclinic phase of CuO with a maximum diffraction of (101) plane. SEM images depict the less severe agglomeration of particles for the doped TiO2 as compared to the anatase TiO2. The UV–visible spectra reveal a direct band gap shift of 3.35 eV (pure TiO2) to 3.26 eV (doped TiO2). From the PL study, the blue shaded emission is perfectly derived for anatase TiO2 while the color is seen to change to the white zone supporting TiO2-CuO composite formation as depicted by the CIE diagram. The diode parameters such as ideality factor (n) and barrier height (Φb) are calculated with the help of I–V characteristics. This only reported novel effort on screen-printed TiO2-CuO thick film may help in manufacturing possible LEDs for optoelectronic applications.

Exploration of impact of thermal condition on microstructural-optical- electrical properties of Ni doped CdS thin films

In this study, Ni-doped cadmium sulfide films were deposited onto ITO substrate using spray-pyrolysis. The effects of annealing(450 °C) on the opto-electrical properties of deposited thin films were investigated.The band gap of films was estimated using absorption spectroscopy, and it decreased from 2.88 eV and 2.81 eV with annealing. The effect of annealing on refractive index and crystal size was also studied. Additionally,the dispersion of refractive index is calculated in terms of Wemple-DiDomenico approch. Third order susceptibility and nonlinear refractive index are calculated of Ni doped CdS films.The electrical properties of the films were characterized using the four-probe method, and the conductivity was found to increase with annealing temperature. The fabricated Ag/Ni:CdS/ITO Schottky diode was tested under illumination conditions, and the empirical diode parameters were influenced by annealing temperature. The morphological and elemental composition analysis of the Ni-doped CdS films was carried out using FESEM and EDS analysis.

Parameters Extraction of Single Diode and Double Diode Models Using Analytical and Numerical Approach: A Comparative Study

ABSTRACT This review paper provides a comparative study between analytical and numerical approaches. The purpose is to estimate the unknown parameters of the single diode and dual diode models. Nine of the most common models are examined in depth, detailing the parameter calculated, the most important approximations characterizing each model, and the calculation process. The effectiveness of the methods studied is assessed under various temperatures and solar irradiation conditions for three types of PV modules using various technologies, such as single-crystalline (CS6V225M), multi-crystalline (CS6P265), and thin film (ST40). The quality of the models fitting to the measured data is assessed by statistical analysis. Results of the study indicate that (1) the temperature exhibits a fairly low impact on the key points of the I–V characteristics of the solar panel, particularly under short and open-circuit conditions, and that (2) the open-circuit voltage at low solar irradiance, as shown in I–V curves, is underestimated. The results of the simulation show that the performance in terms of accuracy varies from one technology to another and the same technology varies with the conditions of temperature and solar irradiation. It is expected that this work will be useful to update the knowledge in the field of PV modeling and simulation.

Growth and characterization of screen printed TiO2–CuO thick films for optoelectronic applications

We herein report, the deposition of pure and CuO doped TiO2 thick films on glass slides by a cost effective screen printing process, which were then sintered to obtain desired stochiometric composition. Different analytical approaches were used to reveal the precise structural, morphological, optical and electrical characteristics information of pure TiO2 and TiO2–CuO thick films. X-ray diffraction (XRD) patterns exhibit the formation anatase phase of TiO2 and monoclinic phase of CuO. Raman spectra show four TiO2 anatase phase modes only in 100–800 cm−1 region. Infrared (IR) transmittance spectra of these samples recorded in 4000–400 cm−1 region also showed weak, very weak and medium intensity stretching and bending modes of O–Ti–O and Ti–O–Ti bond groups of TiO2 only in 700–400 cm−1 region which further supported the formation of TiO2 anatase phase only. Scanning electron microscopy (SEM) images indicate porous surfaces morphology, irregular shaped as well as size polygonal and spherical shaped particles with tendency to form aggregates along with the EDS analysis that confirms proper composition of the films. The optical band gap energies were derived from diffused reflectance spectroscopy and photoluminescence (PL) spectra. They showed a red shift in peak positions which caused reduction in band gap energy. The CIE diagram clearly depicted blue-green and white emissions. I–V characteristics has been used for calculation of the diode parameters such as ideality factor (n) and barrier height (Φb). The extracted results such as band gap, particle size and electrical parameters suggest that the TiO2–CuO thick films can be used in photovoltaic applications.