Diode Resistance Research Articles

Realization of diode structures on paper: An example of papertronics

A possibility of fabricating paper/Ag/CdTe/Au Schottky and paper/Ag/CdTe/CdS/In p-n junction diode structures has been demonstrated here. Ag (∼5 μm), CdTe (∼50 μm), CdS (∼45 μm), Au and In dots (∼5 μm) were deposited on the cellulose using appropriate stainless-steel masks to obtain the requisite diode structures. The band gaps of the CdTe and CdS layers were ∼1.55 eV and ∼1.45 eV, respectively. Current-voltage (I-V) characteristics of the paper/Ag/CdTe/Au Schottky and paper/Ag/CdTe/CdS/In p-n junction diodes were recorded at room temperature. Ideality factor (n), series resistance (RS) and barrier height (φb) of the respective diodes were computed. The barrier height (φb) and ideality factor (n) computed from current-voltage characteristics were found to be 0.74 eV and 1.8, respectively at room temperature. Series resistance and φb computed by using Cheung-Cheung method were ∼177 Ω and ∼0.45 eV, respectively. They are comparable to the resistance derived from a modified Norde method. The fabricated diodes were reproducible and stable for a few months. These diode structures were tested in an open environment at room temperature and showed no noticeable ageing effect.

Design and experimental analysis of a novel thermal diode with asymmetric heat transfer inspired by feather

To overcome the limitation of isotropic heat transfer of traditional heat pipes, a novel thermal diode with asymmetric flow resistance vapor channel inspired by the goose feather fibers is proposed in this study. The thermal performance of novel thermal diode is experimentally investigated. Results show that under the wide range of operating conditions, the thermal resistance of one end surpasses the thermal resistance of the other end, indicating its excellent thermal rectification capability. Under the filling ratio of 10 % and heating power of 7.5 W, the maximum thermal resistance of the thermal diode is 5.23 times the minimum thermal resistance, demonstrating excellent asymmetric heat transfer performance. Experimental results demonstrate that the novel thermal diode proposed in this study can easily change its unidirectional heat transfer direction by simply adjusting the internal filling ratio, showing significant application potential in the fields of thermal control system.

Electrically switchable metamaterial analogue to electromagnetically induced transparency

In this paper, we propose an active electromagnetically induced transparency-like (EIT-like) metamaterial to investigate the electrically switchable behaviors. The EIT-like metamaterial is constructed by a “bright” comb-line resonator side-coupled with a “dark” split-ring resonator. The “bright” and “dark” resonators are individually or simultaneously soldered with PIN diodes. The diodes are connected with DC voltage sources through conducting wires. By adjusting the bias voltage within the range of 0.0–1.2 V, the resistance of PIN diode can be changed from 9000 to 1 Ω, thereby dynamically modulating the EIT-like spectrum. Both simulation and experiment results indicate that this active configuration can generate remarkable multi-band amplitude modulations on the EIT-like spectrum, and a significant modulation depth of up to 18.3 dB was achieved on the tested transmission through the metamaterial. Moreover, the transformation of transparency-to-absorption and slow light on-to-off switching actions are also obtained via electric biasing the proposed sample. These findings resulted from the EIT-like mechanism, which may promote the development of actively controlled photonic devices.

Dependence of the Silicon Carbide Radiation Resistance on the Irradiation Temperature

The effect of high-temperature electron and proton irradiation on SiC-based device characteristics is being investigated. Industrial integrated 4H-SiC Schottky diodes, each with an n-type base and a blocking voltage of either 600 V, 1200 V, or 1700 V, manufactured by Wolfspeed, are being studied. 0.9 MeV electron and 15 MeV proton irradiation were applied. It has been found that the irradiation resistance of silicon carbide Schottky diodes at high temperatures significantly exceeds their resistance at room temperature. This effect is attributed to the annealing of compensating defects induced by high-temperature irradiation. The parameters of radiation-induced defects are determined using the method of deep level transient spectroscopy (DLTS). Under high-temperature ("hot") irradiation, the spectrum of radiation-induced defects introduced into SiC appears to differ significantly from the spectrum of defects introduced at room temperature. It is suggested that approximately half of the compensation is due to radiation-induced defects formed in the bottom part of the bandgap.

Enhanced photodiode performance: Au/boron-dipyrromethene/n-Si/Ag structure unveiling high photosensitivity and efficiency

In this study, the classical boron-dipyrromethene (4,4- difuoro-4-borata-3a-azonia-4a-aza-s-indacene, BODIPY) unit (C1), its halogenated derivative (C2), and disytryl derivative (C3), which are known for their absorption properties in the near-infrared (NIR) region, were synthesized. Chemical and photophysical investigations were carried out to reveal the complex features of the molecules using a range of spectroscopic techniques and their energies were calculated by Density Functional Theory (DFT) with the same basis set. The BODIPY thin films were coated on n-Si substrates using a spin coater to examine the effect of interlayer on photodiode/photovoltaic properties and Au/BODIPY (C1, C2, C3)/n-Si/Ag photodiodes having rectifying behavior were fabricated. The thermionic emission theory (TET) and modified Norde’s functions were utilized to determine the rectification ratio, ideality factor, series resistance, and barrier height values of diodes. The values of barrier height, ideality factor, and rectification ratio at ± 2 V were calculated as 0.81 eV, 1.83 and 2.47x103 for the Au/C1/n-Si/Ag diode, 0.83 eV, 1.63, and 7.06 x103 for the Au/C2/n-Si/Ag diode and 0.84 eV, 1.51 and 2.14x104 for the Au/C3/n-Si/Ag diode in the dark from the TET, respectively. The values of FF (%) and efficiency were calculated as 38 and 1.51 for the Au/C1/n-Si/Ag diode, 47 and 2.03 for the Au/C2/n-Si/Ag diode, and 56 and 3.68 for the Au/C3/n-Si/Ag diode under 100 mW/cm2 illumination, respectively. With remarkable electrical properties, the Au/C3/n-Si/Ag photodiode stood out among the others, performing better in both dark and light conditions. Therefore, the produced diodes based on the BODIPY thin film can be employed as photodiodes/photovoltaics in optoelectronic applications.

(Invited) Minimizing or Maximizing Contact Effects in Organic Electronics

Contact resistance is an umbrella term capturing various current-limiting mechanisms existing at and around metal/semiconductor junctions of an electronic device. Despite its known detrimental impact on the performance of organic, oxide, and 2D semiconductor electronics, a quantitative and predictive description of contact resistance is still lacking. At the same time, recent evidences show that contact resistance can actually provide benefits to certain applications, thus challenging our common belief. This presentation will clarify why contact issues are so critical to the operation of general thin-film systems, and highlight our recent results on re-defining the role of contact resistance in organic diodes and transistors.

Development of novel thermal diode inspired by the structure of venous valve

To increase the unidirectional heat transfer capability of a thermal diode, a novel thermal diode with unidirectional movable valves as vapor channel is proposed based on the structure of venous valves. The thermal performance of this bionic thermal diode was experimentally investigated under different working conditions. The results demonstrate that the bionic thermal diode exhibits a high thermal rectification ratio and strong stability. The best thermal rectification ratio is 10.79, with a forward thermal resistance of 0.26 °C/W and a reverse thermal resistance of 2.86 °C/W, at a heating power of 15 W and a filling ratio of 15 %. The temperature distribution indicated that, under the reverse heat transfer mode, the vapor was obstructed at the first valve, leading to the high thermal resistance of thermal diode. Additionally, the effect of inclined angle on the thermal performance of thermal diode was also investigated. This study provides a novel approach for the design of thermal diodes.

Effect of the insertion of silver nanoparticles on the performance and electrical features of Ag/SiNWs Schottky diode

In this paper, we studied the effect of the passivation of silicon nanowires (SiNWs) by silver nanoparticles (AgNPs) on the efficiency of Ag/SiNWs/Si Schottky diodes. SiNWs are obtained by one-step Ag-assisted chemical etching method. AgNPs were deposited on SiNWs using an electroless dipping method. Schottky junction devices have been successfully made using silicon nanowires coated with silver nanoparticles. The current–voltage (I-V) characteristics of Ag/AgNPs-SiNWs Schottky diode have been investigated by varying the immersion time in silver nitrate solution from 1 to 5 min. The I-V characteristics presented in logarithmic scale confirmed the domination of SCLC conduction mechanism at high voltage. The ideality factor (n), height of potential barrier (φb) and series resistance (Rs) of diodes are calculated by adopting the Cheung method. Compared to the Ag/SiNWs Schottky junction, the diode that presents AgNPs at the interface shows a significant improvement in electrical parameters. The potential barrier reaches 1.09 eV and the ideality factor is reduced to 2.64 with the presence of AgNPs for an immersion time of 1 min. Norde’s equation has also been used to calculate the series resistance and the potential barrier. The results obtained by Norde method are slightly shifted compared to those found by Cheung functions while the findings concerning the optimization of the immersion time are practically the same.

Influence of Microwave and Magnetic Fields on the Electrophysical Parameters of a Tunnel Diode

In this paper, we studied the effect of an electromagnetic field of an ultrahigh frequency on the I–V characteristics of tunnel diodes. The influence of thermionic current on the change in the ratio of the values of tunnel currents at depth and the peak formed in the tunnel diode as a result of a strong electromagnetic field and on the change in the ratio of the values of tunnel currents at the highest and lowest points without exposure to a strong electromagnetic field. The I–V characteristics of a tunnel diode under the action of a microwave field is determined based on the theory of Knott and Demassa and the Tsu-Esaki model. The characteristics of the Tsu-Esaki and Karlovsky models used to determine the effect of the tunnel current in the extremely high frequency field (EHF) are shown. Chynoweth's model and Knott and Demassa's theory have shown that in germanium-based tunnel diodes, under an extremely high frequency (EHF) field, the amount of excess current generated in the tunnel diode increases. According to the Tsu-Esaki theory and Knott and Demassa theory is found to decrease the value of the differential resistance of a tunnel diode with a p-n junction under the action of a microwave field, regardless of the type of heterostructure or doping level. According to the Tsu-Esaki theory and Knott and Demassa found decrease in the diffusion capacitance of a tunnel diode with a p-n junction under the action of a microwave field, regardless of the type of heterostructure or doping level. A decrease in the transparency coefficient due to an increase in the internal field at the p-n junction boundary of a Ge-based tunnel diode under the action of a microwave field has been established. A formula is determined for determining the total current of a tunnel diode under the action of both microwave and magnetic fields, taking into account the transparency coefficient of the tunnel diode.

Direct observation of radio-frequency negative differential resistance in GaN-based single drift region IMPATT diodes

We report the direct observation of radio-frequency negative differential resistance, via on-wafer S-parameter measurements, in GaN-based impact ionization avalanche transit time (IMPATT) diodes. Clear signatures of reflection gain are observed from 18.7 to 30.6 GHz. These observations have been made possible by suppressing the reverse leakage current (and thereby parasitic shunt conductance) by optimization of the fabrication process, in conjunction with the use of pulsed measurements to suppress device self-heating. Consistent with avalanche-dominated behavior, the measured DC reverse bias current–voltage measurements show a positive temperature coefficient of breakdown. For the high-frequency on-wafer characterization, pulsed-bias S-parameter measurements with low (0.0067%) duty cycle were used to mitigate thermal effects. The measured avalanche frequency aligns closely with theoretical predictions based on Gilden and Hines' small signal model [Gilden and Hines, IEEE Trans. Electron Devices ED-13(1), 169–175 (1966)], measured impact ionization coefficients [Cao et al., Appl. Phys. Lett. 112(26), 262103 (2018)], and experimental saturation velocity measurements [Bajaj et al., Appl. Phys. Lett. 107(15), 153504 (2015)]; this excellent agreement confirms IMPATT operation and provides insights needed to further optimize device performance.

Single-event burnout in homojunction GaN vertical PiN diodes with hybrid edge termination design

GaN devices play a major role in modern electronics, providing high-power handling, efficient high-frequency operation, and resilience in harsh environments. However, electric field crowding at the edge of the anode often limits its full potential, leading to single-event effects (SEEs) at lower bias voltages under heavy ion radiation. Here, we report on the performance of homojunction GaN vertical PiN diodes with a hybrid edge termination design under heavy ion irradiation, specifically, oxygen ions, chlorine ions, Cf-252 fission fragments, and alpha particles from an Am-241 source. The unique hybrid edge termination (HET) design provides better electric field management, preventing breakdown from occurring at the edge of the anode at lower voltages. The results of this study reveal that these devices exhibit excellent tolerance to 12-MeV oxygen and 16-MeV chlorine ions, owing to their low linear energy transfer (LET) and range in GaN. However, single-event burnout (SEB) is observed during the Cf-252 exposure at about 50% of the diodes' electrical breakdown voltage due to the presence of higher LET and longer-range ions. Optical and scanning electron microscopy (SEM) reveal that the damage that caused by SEB lies close to the center of these devices rather than the anode edge. Devices with junction termination extension (JTE) instead of HET edge termination also show similar SEB when irradiated with Cf-252 fission fragments. Physical damage due to SEB occurs at the edge of the anode for these devices. These comparative results show the benefits of HET for enhancing the resistance of GaN-based PiN diodes to heavy ion irradiation.

Determination of the Temperature and Thermal Resistance of a Half-Disk Laser Diode by Measuring Pulsed Current-Voltage Characteristics

Determination of the Temperature and Thermal Resistance of a Half-Disk Laser Diode by Measuring Pulsed Current-Voltage Characteristics

Impact of Current on the Parallel Resistance and Junction Capacitance of Light-Emitting Diodes

Impact of Current on the Parallel Resistance and Junction Capacitance of Light-Emitting Diodes

(Invited) Vertically Stacked Graphene Junction Diodes

Graphene is expected to be nanomaterial of the post-silicon era because of its numerous advantageous properties. The single crystal graphene thermally grown on SiC substrate is considered the most promising platform for future electric devices. Large area epitaxial graphene on SiC substrate has been successfully fabricated using high-temperature rapid thermal annealing [1]. In this study, we present vertically stacked graphene junction diodes fabricated using direct bonding technique [2–4]. Figure 1(a) shows the schematic of a stacked graphene junction diode. Two graphene layers on SiC are directly bonded to each other. Gold–coated contact pins are attached to the graphene surface to establish ohmic contact. The graphene samples and contact probes are fixed by acrylic molds. Strong nonlinear current–voltage (I-V) characteristics are observed for this simple device configuration, as shown in Fig. 1(b). In the low bias voltage (Vb) region, the resistance of the graphene diode is approximately 20 GΩ. The current abruptly increases when the bias voltage is increased to approximately 30 V. The two-terminal resistance at a high bias voltage (100 V) is approximately 21 kΩ. The vertically stacked graphene junction exhibits bidirectional thyristor-type characteristics with a high on-off ratio of approximately 106. The Fowler–Nordheim (F-N) tunneling phenomenon is observed in the sub-threshold region. The gap distance estimated from the F-N plot is approximately 6 nm, which can be attributed to the large off resistance. The Coulomb force generated by applying the bias voltage causes the two graphene layers to attract each other, resulting in an electrically conductive state. The junction voltage (Vj) of the device was measured using a four-terminal configuration. As shown in Fig. 1(c), negative resistance is observed in the low-resistance region. The effective internal resistance of the junction diode is reduced to approximately 450 Ω. The off resistance of the diodes is considerably modified by the initial distance between the graphene layers. However, the I-Vj characteristics in the negative resistance region are identical for each device. This result suggests that the cause of the negative resistance phenomena is closely related to the band structure of graphene. A vertically stacked graphene junction diode with a high on-off ratio was demonstrated. The main component of the diode comprised a pair of single-crystal graphene layers fabricated through direct bonding. The negative resistance of the graphene diode presents new possibilities for the application of functional devices, such as terahertz emitters.[1] T. Aritsuki, et al., Jpn. J. Appl. Phys. 55 (2016) 06GF03.[2] J. Du, eta al., Jpn. J. Appl. Phys. 58 (2019) SDDE01.[3] N. Murakami, et al., Jpn. J. Appl. Phys. 60 (2021) SCCD01.[4] M. Ohi, et al., Jpn. J. Appl. Phys. 62 (2023) to be published. Figure 1

MICROWAVE MIXER ON RECTANGULAR WAVEGUIDES PARTIALLY FILLED BY DIELECTRIC

The article investigates and calculates the characteristics of microwave mixers on rectangular waveguides partially filled by dielectric. Presents diagrams of promising combined microwave radio engineering systems - two options for constructing mobile digital troposcatter-radiorelay stations, the antenna-feeder paths of which are implemented on rectangular waveguides partially filled by dielectric. At research of microwave mixers, suppression and the use of the mirror frequency are taken into account. The analysis of researches of microwave mixers is carried out. The design of a balanced-type microwave mixer based on rectangular waveguides partially filled by dielectric is developed. The mixer is used to convertion the microwave signal into an intermediate frequency signal. The signal conversion of the mixers takes place on the non-linear active resistance of the semiconductor diode. In article, an open nonlinear structure is used as such a diode. The following main parameters of microwave mixers are investigated: conversion losses, noise factor, operating frequency band, signal suppression at the mirror frequency. The conversion losses are determined for various mirror channel suppression conditions. Phase methods of mirror frequency suppression are considered, which are most suitable for the waveguide implementation of microwave mixers. A scheme of a microwave mixer of a balance type with a phase method for suppressing the mirror frequency is presented. The article notes that for significant suppression of the mirror frequency of more than 30 dB, a double frequency conversion mixer is used. A diagram of a slotted bridge based on rectangular waveguides partially filled by dielectric is presented. The dependences of the input impedance of the mixer, the impedance of the mixer at the intermediate frequency, the impedance of the mixer at the mirror frequency by the power of the local heterodyne are plotted.

Hybrid Data-Mechanism Modeling for Power Loss of a Boost Converter

Parameter design is the premise to ensure the optimal performance of power electronic converters, which depends on the accuracy of the established model. However, there is still many issues for improvements in modeling methods for the parameters design of power electronic converters. Due to the lack of key mechanism and the uncertainty of parameters, the existing modeling method shows poor accuracy or efficiency. In order to simplify the process and improve the accuracy of the existing modeling method, this paper proposes a hybrid data-mechanism modeling (HDMM) method for power loss of a typical power electronic converter, Boost converter, which is with UC3842 control chip. Based on the main loss from inductor, switch tube, diode and sampling resistance, the mechanism power loss modeling of Boost converter is built. Besides, the artificial neural network (ANN) is used to learn from the sampled data and train the data-driven model. To improve the accuracy of the mechanism model, the HDMM for power loss of Boost converter is established by modification of data-driven model with limited data. Through the proposed HDMM method, the mechanism modeling method and data-driven method are well combined and the HDMM has the advantage of high accuracy and strong generalization. In the end of this paper, feasibility and accuracy of the proposed HDMM method have been verified by hardware experiments.

Online die temperature measurement using S-parameters in GaN-based power converters

Die temperature (Tj) measurement of GaN HEMTs is of high interest to enable reducing design margin and the implementation of reliability driven control schemes and protections. On-state resistance (Rds,on) has been identified as a relevant thermo-electric sensitive parameter (TSEP) for Tj measurement requiring no extra temperature sensor. It is commonly measured in time-domain, based on the on-state voltage drop and the load current. In this work, the Tj of a GaN-on-Si power IC in a dc-dc converter is deduced from measurements conducted online, directly in the frequency domain using RF injection and S-parameter measurements. Thereby, the stimulus is injected on top of the processed power to probe either Rds,on, or the resistance of an on-chip Schottky diode used as thermal sensor. Temperature dependent experimental validation up to 150 °C is performed on a switching dc-dc power converter, validating the approach for online temperature measurement using RF injection.

Wideband switchable linear polarization rotator based on metasurface

The realization of dynamic polarization rotation based on the metamaterial or metasurface is always a concerned issue in electromagnetic manipulation. In this Letter, a transmission-type switchable metasurface is proposed, which can rotate the linear polarized (LP) wave to arbitrary angle among ±45° in a wide frequency band. The polarization rotation metasurface (PRM) consists of a polarization conversion surface and a partially reflective surface. By controlling the resistances of PIN diodes, the PRM can change the polarization angle of transmitted LP wave. To verify the design, a prototype of the proposed PRM is fabricated and tested, and the simulated and measured results are in good agreement. According to the measured results, the fractional bandwidth at each state of prototype is larger than 20.4%. The overlapping operational band of the prototype is from 3.03 to 3.60 GHz, where the transmission coefficient remains higher than –2 dB, and the axial ratio of transmitted wave is higher than 15 dB. The proposed design may have the application potential in target detection, wireless communication, and polarimetric imaging.

Penentuan Resistansi Dinamis Pada Dioda Silikon 1n4002 Melalui Pengukuran Karakteristik Arus Terhadap Tegangan (I-V) Berbasis Arduino Mega 2560

An instrument for measuring I-V characteristics and determination of the dynamic resistance of a Silicon 1n4002 diode based on Arduino Mega 2560 has been successfully developed. This measurement was carried out by increasing the bias voltage periodically from 0 V to 5 V and observing the resulting forward voltage and forward current for each increase in the bias voltage. There is an increase in current when the diode voltage reaches 0.7 V, which is the diode barrier voltage. This happens if the limit resistor installed in the circuit is 100 Ω. The largest dynamic resistance value is 593.069 Ω, which is below the forward voltage of 0.6 V. Furthermore, the smallest dynamic resistance value is 2.293 Ω which is above the forward voltage of 0.7 V. The greater the value of the current flowing in the diode circuit, the smaller the dynamic resistance value of the diode and the smaller the value of the current flowing, the greater the dynamic resistance of the diode.

Design and analysis of actively tunable absorbers combined with diodes and magnetic material

A periodic structure absorber combined with diodes and magnetic material is proposed in this paper. By changing the power supply voltage, the absorbing performance of the absorber can be changed to adapt to different electromagnetic environments. The influence of the diode resistance variation for the absorption property of the absorber is explored by the symmetry model and the equivalent circuit model, and the role of the diode is cleared in realizing the tunability of the absorber. The design of the branch structure circuit creates two absorbing peaks in the absorber, and due to the adding of the magnetic material, the structure proposed in this paper has the advantages of wider adjustable frequency and lower frequency absorption peaks. Experiments show that the absorption peak of the absorber changes from 4.3 GHz to 8.8 GHz when the bias voltage is changed from 0 to 9 V and the reflectivity envelope covers a broadband of 4–4.6 GHz and 6–9.3 GHz below −10 dB.