Pn Junction Diode Research Articles

Near zero-field magnetoresistance and defects in gallium nitride pn junctions

As gallium nitride (GaN) grows in importance, an atomic scale understanding of device performance is of significant relevance. In this paper, we present the first observations of near zero-field magnetoresistance (NZFMR) detecting electrically active defects in GaN-based devices. Our observations involve recombination current in GaN pn junction diodes. We attribute the NZFMR response to gallium vacancies.

Field management in NiO x /β-Ga2O3 merged-PIN Schottky diodes: simulation studies and experimental validation

In recent years, p-type NiO x has emerged as a promising alternative to realize kilovolt-class β-Ga2O3-based PN junction diodes. However, only a handful of studies could realize β–Ga2O3-based unipolar diodes using NiO x as a guard ring or floating rings. In this work, we investigate the device design of NiO x /β-Ga2O3 unipolar diodes using the technology computer aided design simulations and experimental validations. We show that a systematic electric field management approach can potentially lead to NiO x /β-Ga2O3 heterojunction unipolar diode and offer enhanced breakdown characteristics without a severe compromise in the ON-state resistance. Accordingly, the NiO x /β-Ga2O3 heterojunction diode in the merged-PIN Schottky configuration is shown to outperform the regular Schottky diode or junction barrier Schottky diode counterpart. The analysis performed in this work is believed to be valuable in the device design of β-Ga2O3-based unipolar diodes that use a different p-type semiconductor candidate as guard rings and floating rings.

Carbon nanotube thin film pn junction diode with high-temperature tolerance using chemical dopants

Abstract Chemical doping of carbon nanotubes (CNTs) by adsorption with high-temperature-tolerant molecules is required for the fabrication of various types of electronic devices for their performance maintenance under harsh thermal conditions during the fabrication and operation processes. Here, we demonstrate the fabrication of CNT thin film pn junction diodes using a combination of 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as a p-dopant and a complex salt of potassium hydroxide and benzo-18-crown-6 ether as an n-dopant. The fabricated devices demonstrated a reasonably stable rectifying behavior, even after heating to 200 °C for 300 min.

Rapid fabrication approach for active photonic devices by employing spin-on dopants.

Modulation based on the plasma dispersion effect can be achieved by controlling free carriers in the optical region with the aid of pn junction diodes. The embedded diodes are commonly realized with ion implantation, which is only available in large facilities with significant costs and sparse schedules. A cost- and time-effective method is reported in this study to improve flexibility during the development phase. The suggested process is based on spin-on dopants and free of a hard mask for further simplification. Following the implementation of devices with this method, electrical and optical characterization results are presented.

Heteroepitaxially grown homojunction gallium oxide PN diodes using ion implantation technologies

Although advancements in n- and p-doping of gallium oxide (Ga2O3) are underway, the realization of functional pn diodes remains elusive. Here, we present the successful fabrication of a Ga2O3 pn diode utilizing ion implantation technology. The Ga2O3 epilayers were grown on c-plane sapphire substrates by metalorganic chemical vapor deposition (MOCVD). P-type conductivity Ga2O3 epilayer, confirmed by Hall effect analysis, was achieved by phosphorus (P) ion implantation followed with a rapid thermal annealing (RTA) process. This p-Ga2O3 epilayer reveals a significant reduction in resistivity (<106) compared to undoped Ga2O3, demonstrating the successful inclusion and activation of P within the crystal lattice. X-ray diffraction analysis shows that the Ga2O3 epilayers were grown in high crystal quality. Although the crystallinity of Ga2O3 was slightly degraded after P ion implantation, the structure was recovered to high-quality crystal after RTA treatment. For the device structure, p-type Ga2O3 was formed first, followed n-type Ga2O3 regrowth to create a pn junction diode. The obtained results demonstrate a built-in voltage of 4.8 V, 4.2 V, and 4.308 V from simulation, fabricated pn diodes measured by I–V and C–V, respectively. A high breakdown voltage of 900 V was also obtained for the lateral pn diode grown on sapphire substrate. As concerning temperature stability, I–V curves of Ga2O3 pn diode were measured from 25oC to 150oC in steps of 25 °C. At elevated temperatures, for both forward and reverse biases, consecutive increasing currents were measured. These could be resulted from dominant diffusion and drift currents over recombination current at a given bias. In addition, the reverse current saturated (@V > 3kT/q) and remained very low at 2✕10−8 A, as the diode operated at 150oC. The behavior could be due to Ga2O3 being a wide bandgap material.

Modulation of Diamond PN Junction Diode with Double-Layered n-Type Diamond by Using TCAD Simulation

This study proposed a novel double-layer junction termination structure for vertical diamond-based PN junction diodes (PND). The effects of the geometry and doping concentration of the junction termination structure on the PNDs’ electrical properties are investigated using Silvaco TCAD software (Version 5.0.10.R). It demonstrates that the electric performances of PND with a single n-type diamond layer are sensitive to the doping concentration and electrode location of the n-type diamond. To further suppress the electric field crowding and obtain a better balance between breakdown voltage and on-resistance, a double-layer junction termination structure is introduced and evaluated, yielding significantly improved electronic performances. Those results provide some useful thoughts for the design of vertical diamond PND devices.

Electronic transport characteristics and nanodevice designs for β-HfNCl monolayer

The mechanical properties, electronic structure, electric transport and optoelectronic properties of a recently predicted wide bandgap semiconductor β-HfNCl monolayer are systematically studied by means of first-principles calculations. β-HfNCl monolayer is isotropic in mechanical properties, whose calculated Young’s modulus, shear modulus, and layer modulus of β-HfNCl monolayer are 128.9–129.2, 44.28, and 119.46 N m−1, respectively. An appropriate tensile strain (i.e., beyond 3 %) can induce a transition from indirect bandgap to direct bandgap. In addition, we construct several conceptual nanodevice structures based on β-HfNCl monolayer, such as pn-junction diodes, pin-junction field-effect transistors (FETs) and phototransistors. The electronic transport results reveal that the pn-junction diodes have obvious rectification effect and strong electric anisotropy. Their rectification ratios and electric anisotropy ratio (η) can reach up to 106 and 3.69, respectively. The FETs have an obvious field-effect behavior with a slightly lower rectification ratio (105). Moreover, we investigate the photoelectric response of the phototransistors of β-HfNCl monolayer under the illumination of light. They have a strong response to the light whose energy is larger than the violet light, indicating that the β-HfNCl monolayer can be a platform to detect the ultraviolet light. These findings provide crucial insights into the potential applications of β-HfNCl monolayer in electronic and optoelectronic devices.

14C diamond as energy converting material in betavoltaic battery: A first principles study

The application of radioactive semiconductors is a potential way to improve the performance of betavoltaic battery. The stability and band structure of decayed 14C diamond are investigated by density functional theory. After the decay, the 14C atoms are substituted by nitrogen atoms, and it can be seen that the corresponding C63N1 and C62N2 structures have larger lattice constants and become more unstable. The C63N1 structure is a metallic system instead of an indirect bandgap semiconductor. Different C62N2 configurations have either metallic or indirect bandgap semiconductor properties, and the bandgaps are significantly lower than those of pure diamond. The 14C diamond–12C diamond betavoltaic battery switches between a pn-junction and p-type Schottky diode with higher short-circuit current.

On band-to-band tunneling and field management in NiOx/β-Ga2O3 PN junction and PiN diodes

Due to the non-availability of p-type β-Ga2O3 films, p-type NiO x is gaining attention as a promising alternative to complement the n-type β-Ga2O3 films. This work investigated the band-to-band tunneling (BTBT) related reverse leakage current in NiO x /β-Ga2O3 PN junction diodes. The analysis reveals that a low barrier between the valence band maxima of NiO x and conduction band minima of β-Ga2O3 may promote direct BTBT and trap-assisted BTBT currents during the reverse bias. On the contrary, NiO x /β-Ga2O3 diodes in PiN configuration offer a wider BTBT depletion width and lower peak electric field, lowering the reverse leakage current by orders of magnitude. Thus, we show that NiO x /β-Ga2O3 heterojunction diodes in PiN configuration offer better field management strategies and suppression of the reverse leakage. The analysis performed in this work is thought to be valuable in informing device-design of NiO x /β-Ga2O3 heterojunction diodes for future high-power applications.

Trenched diamond PN junction diode with enhanced conductance modulation effect designed by simulation

In this work, Silvaco TCAD is used to design a vertical trenched diamond PN junction diode. Comparing with the conventional beveled PN junction diode, the PN junction on both trench and mesa of the trenched PN junction diode contribute to the conduction, resulting in the obvious enhanced current density. It reveals that the doping concentration and thickness of n-type diamond, as well as the length ratio between trench and mesa, have significant effects on the performances of the trenched PN junction diode. A diamond PN junction diode with good balance between Ron and VBD has been realized after optimizing those parameters. Those results provide some valuable references for the design and fabrication of diamond PN junction diodes.

Enhanced magnetometry with an electrically detected spin defect ensemble in silicon carbide

Spin defects in solid-state sensors are a highly promising platform for quantum sensing, a field with far-reaching applications in a variety of industries. Here, we investigate the magnetic sensitivity of a spin defect ensemble detected electrically in a silicon carbide pn-junction diode utilizing the hyperfine-induced spin-mixing effect observed in the vicinity of zero magnetic field. To enhance the baseline sensitivity, we employ above bandgap optical excitation to generate additional electron-hole pairs as well as a balanced detection scheme to reject common-mode noise, with an ultimate sensitivity of 30 nT/Hz achieved. Both techniques are demonstrated to greatly enhance the magnetic sensitivity of the device by a total factor of ∼24, paving the way toward sub-nanotesla magnetic field sensitivities with electrical detection.

Simulation Study to Enhance the Efficiency of Switching Devices using the Combinations of Diodes in Various Networks

AbstractIn this communication, PSpice simulation software is used to design and characterize reverse biasing modes in series and parallel combinations. Using multiple diodes of similar types, how the breakdown voltage and power dissipation vary in parallel and series modes in reverse bias is investigated. In this paper, correlation equations and correlation factors between voltage and current in both series and parallel combinations using n = 1‐5 diodes in reverse bias are also found. The second‐order correlation equation between voltage and current provides a new way for designing new networks of PN junction diodes for better power gain. The mathematical formulation for applied voltage and average current of n = 1‐10 diodes in parallel and series combinations is also calculated, which can help researchers to design new network circuits for switching devices in the electronics industry.

Silicon Self-Switching Diode (SSD) as a Full-Wave Bridge Rectifier in 5G Networks Frequencies.

The rapid growth of wireless technology has improved the network's technology from 4G to 5G, with sub-6 GHz being the centre of attention as the primary communication spectrum band. To effectively benefit this exclusive network, the improvement in the mm-wave detection of this range is crucial. In this work, a silicon self-switching device (SSD) based full-wave bridge rectifier was proposed as a candidate for a usable RF-DC converter in this frequency range. SSD has a similar operation to a conventional pn junction diode, but with advantages in fabrication simplicity where it does not require doping and junctions. The optimized structure of the SSD was cascaded and arranged to create a functional full-wave bridge rectifier with a quadratic relationship between the input voltage and outputs current. AC transient analysis and theoretical calculation performed on the full-wave rectifier shows an estimated cut-off frequency at ~12 GHz, with calculated responsivity and noise equivalent power of 1956.72 V/W and 2.3753 pW/Hz1/2, respectively. These results show the capability of silicon SSD to function as a full-wave bridge rectifier and is a potential candidate for RF-DC conversion in the targeted 5G frequency band and can be exploited for future energy harvesting application.

Van der Waals interfaces in multilayer junctions for ultraviolet photodetection

Developments in semiconductor science have led to the miniaturization and improvement of light detection technologies for many applications. However, traditional pn-junctions or three-dimensional device geometries for detection of ultraviolet (UV) light are still limited by the physical properties of the semiconductors used, such as the small penetration depth of UV light in silicon. Van der Waals (vdW) semiconductors and their pn-junctions can offer an alternative solution due to their optical properties and thin pn-junction region. Here, we report on a multi-layer junction that combines single layer graphene and vdW semiconductors (p-GaSe and n-In2Se3) with strong optical absorption in the UV range. The junctions have broadband spectral response (0.3-1.0 μm) and high photoresponsivity under forward and reverse bias, or without any externally applied voltage. The photoresponse differs from that of a traditional pn-junction diode as it is governed by charge transport across thin layers and light-current conversion at three vdW interfaces (e.g. the graphene/GaSe, GaSe/In2Se3 and In2Se3/graphene interfaces). The type-II band alignment at the GaSe/In2Se3 interface and electric field at the three vdW interfaces are beneficial to suppress carrier recombination for enhanced photoresponsivity (up to ~102 A/W) and detectivity (up to ~1013 Jones), beyond conventional UV-enhanced silicon detection technology.

Numerical Investigation on Hole-Injection Characteristics of NiO/SiC Heterojunction

Numerical investigation on hole-injection characteristics of NiO/SiC heterojunction is carried out in this paper. Theory analysis and numerical simulation both indicate the excellent hole-injection characteristic of p-NiO/n-SiC heterojunction. The pn junction diode and pnp phototransistor are constructed and simulated to evaluate hole-injection characteristics p-NiO/n-SiC heterojunction. The results indicate that the p-NiO/n-SiC heterojunction shows great potential advantage in enhancing current gain of pnp phototransistor. By using NiO/SiC heterojunction as the emitter junction, the current gain of SiC based pnp phototransistor can be increased by about 96.3 times.

Impact of phase transformation on MoS2 thin films on high temperature and its concomitant role in In-MoS2/P-Si structured PN junction diodes

In this paper, we focus on thin films (TFs) growth MoS2 material coated with different concentrations of Indium (In) (2, 4, and 6 wt %) by adopting the JNSP technique with the optimized temperature at 550 °C. The XRD pattern of prepared samples revealed the polycrystalline nature with improved grain size along with In concentrations. The chemical structures of the typical RAMAN spectra of MoS2, and In/MoS2 were confirmed by Raman spectra. FE-SEM photographs of the higher concentrated TFs displayed the rod-shaped structural grains are reduced and replaced by a disintegrated cluster ceramic plate-like structure, and the EDAX spectrum confirmed the elements. The minimum energy band gap of the In–MoS2 films was found to be 2.25 eV with the In 6 wt %. The conductivity increased for the higher concentration of In–MoS2 TFs with elevated corresponding activation energy and resistivity values. The fabricated In–MoS2/p-Si types PN have good electrical behavior for all the diodes specifically, 6 wt% of In added sample yielded a better result.

Portable rain water detecting alarm using ic 555 timer

&#x0D; &#x0D; &#x0D; Everyone wants to stay educated and productive in a world when everything is automated. Water harvesting may also be simply accomplished with the help of automation. In this article, we'll talk about the Rain Alarm project, which is quite important for rainwater gathering. The circuit detects rain by sounding an alert while you are inside the house, allowing us to take appropriate action.This project is a portable rain water detecting alarm designed to protect goods from rain while also conserving water. It uses a rain sensor and a versatile multifunctional IC 555 Timer Chip to detect rain water in rainy conditions. LED, 9V battery, rain sensor, buzzer, 1N4007 PN junction diode, NPN transistor, and other components make up the rain water detection alarm. When the rain starts falling, the rain sensor detects it and the buzzer starts blaring and the LED lights up, and it will automatically reset when the rain stops The ultimate purpose of this project is to use a rain sensor to detect rain falling, and this concept can be used in the home, irrigation field, and cottage industries.&#x0D; &#x0D; &#x0D;

Microcontroller based study of diode thermometers for online demonstration of undergraduate laboratory classes in COVID-19 lockdown

At constant current (I) the forward bias potential (V) of a pn junction diode may be considered to vary linearly with temperature (t) within a temperature range. Based on this property we have constructed diode thermometer using germanium (Ge) and silicon (Si) diodes. The experimental data at constant forward current have been fitted to a straight line for calibration of the diode thermometers using the least square method. Furthermore, the fitting parameters of the straight line have also been used to determine the band gap energy of germanium and silicon and experimental values of band gap for both the semiconductor materials are found to agree well with accepted values.

Spin transport characteristics and photoelectric properties of magnetic semiconductor NiBr&lt;sub&gt;2&lt;/sub&gt; monolayer

Magnetic semiconductor materials have potential applications in spintronic devices. In this work, some nano-device structures based on the magnetic semiconductor NiBr&lt;sub&gt;2&lt;/sub&gt; monolayer (NiBr&lt;sub&gt;2&lt;/sub&gt;-ML) are designed, their spin-resolved transport and photoelectric properties are studied by using density functional theory combined with non-equilibrium Green’s function method. The results show that both the NiBr&lt;sub&gt;2&lt;/sub&gt;-ML PN-junction diodes and sub-3 nanometer PIN-junction field-effect transistors (FETs) exhibit the significant rectification and spin filtering effects in either the armchair or the zigzag direction. The gates can obviously tune the electron transmission of the PIN-junction FETs. The current is significantly suppressed with the increase of gate voltage. In addition, NiBr&lt;sub&gt;2&lt;/sub&gt;-ML has a strong response to the blue and green light, thus its phototransistor can generate a strong photocurrent under the irradiation of blue and green light. The research results in this paper reveal the multifunctional characteristics of NiBr&lt;sub&gt;2&lt;/sub&gt;-ML, which provides an important reference for the application of nickel-based dihalides in semiconductor spintronic devices and optoelectronic devices.

Influence of aluminum ion on the structural, optical, and electrical properties of CuO thin films for the PN-Junction diode application

Pure and (1, 3, and 5 wt%) Aluminum-doped copper oxide(Al:CuO) thin films were prepared using the JNS spray-pyrolysis technique using analytical grade copper chloride and aluminum chloride as a precursor. The monoclinic structure of the CuO film has been confirmed by an X-ray diffraction (XRD) study. The microstructure of the films is analyzed with the help of a scanning electron microscope (SEM). The optical characteristics of the grown films have been examined with the help of UV–vis spectroscopy, from which the bandgap of the materials of the coated films are calculated. Electrical properties such as conductivity and the diode activity of the films are studied using I-V characterization, which shows the improved electrical conductivity with the increase in doping concentration. Diodes are fabricated using pure and Aluminum-doped p-type CuO thin films coated on the n-type silica wafer by the JNS technique, and the rectification behavior is found to improved at a higher doping concentration of Al3+ ions.