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The purpose of this paper is to propose a simple electrothermal model of GaN Schottky diodes, and its usefulness for circuit-level electrothermal simulation of laboratory-made devices is proved.

The compact electrothermal model of this device has the form of a subcircuit for simulation program with integrated circuit emphasis. This model takes into account influence of a change in ambient temperature in a wide range as well as influence of self-heating phenomena on dc characteristics of laboratory-made GaN Schottky diodes. The method of model parameters estimation is described.

It is shown that temperature influences fewer characteristics of GaN Schottky diodes than classical silicon diodes. The discussed model accurately describes properties of laboratory made GaN Schottky diodes. Additionally, the measured and computed characteristics of these diodes are shown and discussed.

The presented model together with the results of measurements and computations is dedicated only to laboratory-made GaN Schottky diodes.

The presented investigations show that characteristics of laboratory-made GaN Schottky diodes visibly change with temperature. These changes can be correctly estimated using the compact electrothermal model proposed in this paper. The correctness of this model is proved for four structures of such diodes characterised by different values of structure area and a different assembly process.

The purpose of this paper is to present the characteristics of novel silicon Schottky barrier (SB) photodiodes (PDs) with aluminium nitride (AlN) (100 nm) nucleation layer.

Comparison was made with conventional silicon SB PDs.

It was found that smaller dark current could be achieved with AlN nucleation layer. It was also found that effective SB height increased from 0.65 to 0.71 eV with the insertion of the AlN layer. The dark leakage current for the Schottky PDs with the AlN layer was shown to be about two orders of magnitude smaller than that for the conventional silicon SB PDs.

It is possible that the detrimental effect of interface states situated near the metal semiconductor interface was less pronounced for the sample owing to the insertion of the AlN nucleation layer.

There is believed to be no other report on silicon SB PDs capped with an AlN layer in the literature. This paper describes the fabricated silicon SB PDs and reports on the electrical characteristics of the devices with an AlN nucleation layer grown at low temperature.

On average, a medium-sized satellite consist of almost 500 sensors where powering these sensors in space in such an unreachable environment is critical. Backing this, a compact energy harvester for powering up distant sensors is discussed here is the purpose of this paper. This is in line with the geostationary satellite-powered using the available electromagnetic energy on the satellite panels in space.

The designed rectenna makes use of a compact wideband receiving antenna operating at the targeted frequency band from 8 to 18 GHz. It also consists of a simple dual diode rectifier topology with a matching circuit, bandpass filter and a resistive load to convert the received radio frequency energy into usable direct current (DC) voltage.

The rectenna measurement is performed using three different configuration setups. This shows that a maximum DC voltage of 1.8 V and 5-10 mV is harvested from rectifier and rectenna (includes antenna and rectifier) when 20 dBm power is transmitted from the transmitting antenna operating at X and Ku band. This makes the rectenna feasible to power wireless sensors in a structural health monitoring system.

The measurements are performed by considering a real-time environment in space in terms of the distance between the transmitting and receiving antenna, which depends on the far-field of the transmitting antenna in a satellite.

This paper aims to present the results of measurements and calculations illustrating mutual thermal coupling between power Schottky diodes made of silicon carbide situated in the common case.

The idea of measurements of mutual transient thermal impedances of the investigated device is described.

The results of measurements of mutual transient thermal impedances between the considered diodes are shown. The experimentally verified results of calculations of the internal temperature waveforms of the considered diodes obtained with mutual thermal coupling taken into account are presented and discussed. The influence of mutual thermal coupling and a self-heating phenomenon on the internal temperature of the considered diodes is pointed out.

The presented methods of measurements and calculations can be used for constructing the investigated diodes made of other semiconductor materials.

The presented results prove that mutual thermal coupling between diodes mounted in the common case must be taken into account to calculate correctly the waveforms of the device internal temperature.

The purpose of this paper is to demonstrate the existence of one suitable oxide phase concurrent with deposition for fabricating a titanium (Ti)/p-silicon (Si) Schottky diode by direct current (DC) magnetron sputtering method.

In this paper, a Ti/p-Si Schottky diode has been fabricated by depositing a Ti film on p-Si substrate by DC magnetron sputtering. Electrical properties of a Schottky junction include three main parameters: ideality factor (n), series resistance (R_s) and barrier height (Φ_b), which were determined by three analysis methods: current–voltage (I-V), Cheung function and Norde function.

As result outcomes of the calculated values by three analysis methods, average values were obtained equal to 2.475, 27.07 kÙ and 0.88 ev. With comparing direct calculation of series resistance with the achieved average value of three analysis methods, it illustrates that without X-ray diffraction (XRD) analysis consideration, it’s possible to deduce at least one oxide phase forming on the Ti layer.

This work fabricates Ti/p-Si Schottky diode by DC magnetron sputtering. By use of downward-arch region of the LnI-V curve, two functions that are known as Norde and Cheung were made with which this study applies these functions and linear region of LnI-V plot each values of n, Φ_b and R_s, except n calculated two times. With comparison of calculated values from two parts of plot, it is clear that Norde and Cheung functions are accurate and the applied method is correct. Also, with direct calculation, the value of R_s and as compared with result from analysis, this study has proved that without XRD plot, certainly simultaneity deposition at least one oxide phase was forming on Ti layer.

The purpose of this paper is to deal with material and technological aspects of SiC diodes assembly in ceramic packages. The usefulness of combinations of different materials and assembly techniques for the creation of inner connection system in the ceramic package, as well as the formation of outer connections able to work at temperatures up to 350°C, were evaluated.

The ceramic package consists of direct bonded copper (DBC) substrate with Cu pads electroplated by Ni or Ni/Au layers on which a SiC diode was assembled by sintering process using Ag microparticles. For the connections inside the ceramic package, the authors used Al/Ni and Au-Au material system based on aluminium or gold wire bonding. The authors sealed the ceramic package with glass encapsulation and achieved a full encapsulation. Outer connections were manufactured using Cu ribbon plated with Ag layer and sintered to DBC by Ag micro particle. The authors investigated the long-term stability of electrical parameters of SiC diodes assembled in ceramic package at temperature 350°C.

The authors have shown that Schottky and PiN SiC diodes assembled with different technologies and materials in ceramic package keep their I-V characteristics unchanged during ageing at 350°C for 400 h.

The SiC diodes assembled into ceramic package with Al/Ni or Au-Au inner electrical connection systems and outer connections system based on Ag microparticles sintering process of Cu/Ag ribbon to DBC substrate can work reliably in temperature range up to 350°C.

This paper aims to present the design of a cantilever beam with various kinds of geometries for application in energy harvesting devices with a view to enhance the harvested power. The cantilever beams in rectangular, triangular and trapezoidal geometries are simulated, designed and evaluated experimentally. A power conditioning circuit is designed and fabricated for rectification and regulation.

The analytical model based on Euler–Bernoulli beam theory is analyzed for various cantilever geometries. The aluminum beam with Lead Zirconate Titanate (PZT) 5H strip is used for performing frequency, displacement, strain distribution, stress and potential analysis. A comparative analysis is done based on the estimated performance of the cantilevers with different topologies of 4,500 mm³ volume.

The analysis shows the trapezoidal cantilever yielding a maximum voltage of 66.13 V at 30 Hz. It exhibits maximum power density of 171.29 W/mm³ at optimal resistive load of 330 kΩ. The generated power of 770.8 µW is used to power up a C-mote wireless sensor network.

This study provides a complete structural analysis and implementation of the cantilever for energy harvesting application, integration of power conditioning circuit with the energy harvester and evaluation of the designed cantilevers under various performance metrics.

The purpose of this paper is to demonstrate the n‐ZnO/p‐Si Schottky photodiodes.

A Zn film was deposited on silicon substrate by dc sputtering deposition technology from high purity zinc (Zn) targets. Then, the Zn films were then annealed under flowing oxygen (O₂) gas environment in the furnace. ZnO nanorods morphologies have been successfully prepared through a simple method. No catalyst is required.

The structures and morphologies of the products were characterized in detail by using X‐ray diffraction, energy dispersive X‐ray, and scanning electron microscopy (SEM). According to experimental results, the current‐voltage characteristics of the device show the typical rectifying behaviour of Schottky diodes. The UV photocurrent measurement was performed using an UV lamp under a reverse bias.

The paper demonstrates that the n‐ZnO/p‐Si diodes exhibit strong rectifying conduct described by the current‐voltage (I‐V) measurement under a dark and illumination conditions.

Boundary limited transport in small compound semiconductor devices is studied within the self‐consistent Monte Carlo method. New stable microscopic models fully accounting for stochastic carrier exchange at boundaries have been developed for ohmic, tunneling, and Schottky barrier boundaries. These new models are demonstrated with applications to the one‐dimensional GaAs resistor, N+‐N‐N+ diode and the N+‐N Schottky diode.

The purpose of the paper is to present a frequency-changing technique to realize a fast start-up radio frequency (RF) energy harvester.

First, a simple analysis of the input impedance of the rectifier circuit is presented, and based on the analysis, it is shown how the input impedance of the rectifier is changed during the rectifier charging. Then, the frequency-changing technique is presented in which the variation of the rectifier input reactance (capacitance) is partly compensated by changing the frequency of the transmitted RF signal. A harvester consisting of a four-stage rectifier and a simple series matching inductor, implemented based on Schottky diode, is employed to verify the technique.

With the input available power of −12 dBm, the simulated and the measured results prove that the proposed frequency-changing method compared to the typical fixed-frequency method shows more than 30 per cent decrease in the transient time to reach 0.5 V output voltage, while the final harvested output voltage is unchanged.

A frequency-changing technique is presented.