Rectification Characteristics Research Articles

Boron atoms migration during epitaxial growth of boron-doped single-crystal diamond

Boron-doped diamond (BDD) films are essential for the fabrication of electronic devices with P+ or P− layers. However, the boron atoms in the intrinsic diamond substrates due to the concentration gradient may affect the height of the Schottky barrier based on these BDD films. BDD films with different concentrations of boron atoms were deposited on chemical vapor deposition (CVD) diamond seeds by microwave plasma chemical vapor deposition. Laser confocal Raman spectroscopy was utilized to investigate the migration of boron atoms during the CVD deposition process. The results indicate that the diffusion depth is below 20 μm with a boron atom concentration of 1020 cm−3 at a deposition time of 10 h. The boron atom diffusion depth is below 8 μm at a fixed CH4/H2 ratio of 2% after 5 h deposition. The characteristic peak of boron atoms is not detected by Raman spectroscopy after 3 h deposition, while the infrared spectrum indicates that the boron atom concentration is more than 1018 cm−3. Consequently, the boron atom concentration and the diffusion depth in CVD seeds can be regulated by controlling the CH4/H2 ratio and the deposition time. Planar diamond-based Schottky diodes based on the prepared P+ or P− layer exhibit distinct rectification characteristics.

Reconfigurable CMOS-Compatible Supercapacitor-Diode Empowering Computation Efficiency for Human-Machine Interaction.

Biological system utilizes unidirectional ion flow to produce and transmit signals. To realize bioinspired artificial intelligence and thus seamless human-machine interaction, ion rectification devices should be developed. Here, a reconfigurable CMOS-compatible supercapacitor-diode (CAPode) is developed by resettling the pseudo-capacitive and electrochemical-double-layer-capacitive components of a lithium-ion pseudocapacitor into the positive and negative voltage regions respectively through engineering the redox peaks. This CAPode exhibits good ion rectification and charge-storage bifunction with high rectification ratio (RR) (RRI~20, RRII~0.83), large areal capacitance (17 mF cm-2) and long cycling stability (5000 cycles). More importantly, two main computing paradigms in the biological system are efficiently realized based on this CAPode by empowering the supercapacitor function into the diode: (I) multivalued ionic logic gates are constructed based on the tunable ion rectification characteristics induced by the bifunction of this CAPode for mimicking the dendritic computing; (II) all-CAPode based reservoir computing is implemented based on the reconfigurable volatile and nonvolatile charge-storage characteristics of this CAPode for mimicking the neuromorphic computing. This work paves a new way towards seamless and high-efficiency human-machine interaction.

Reconfigurable CMOS‐Compatible Supercapacitor‐Diode Empowering Computation Efficiency for Human‐Machine Interaction

Biological system utilizes unidirectional ion flow to produce and transmit signals. To realize bioinspired artificial intelligence and thus seamless human‐machine interaction, ion rectification devices should be developed. Here, a reconfigurable CMOS‐compatible supercapacitor‐diode (CAPode) is developed by resettling the pseudo‐capacitive and electrochemical‐double‐layer‐capacitive components of a lithium‐ion pseudocapacitor into the positive and negative voltage regions respectively through engineering the redox peaks. This CAPode exhibits good ion rectification and charge‐storage bifunction with high rectification ratio (RR) (RRI ~ 20, RRII ~ 0.83), large areal capacitance (17 mF cm‐2) and long cycling stability (5000 cycles). More importantly, two main computing paradigms in the biological system are efficiently realized based on this CAPode by empowering the supercapacitor function into the diode: (I) multivalued ionic logic gates are constructed based on the tunable ion rectification characteristics induced by the bifunction of this CAPode for mimicking the dendritic computing; (II) all‐CAPode based reservoir computing is implemented based on the reconfigurable volatile and nonvolatile charge‐storage characteristics of this CAPode for mimicking the neuromorphic computing. This work paves a new way towards seamless and high‐efficiency human‐machine interaction.

Tellurium Doped p-n Device Fabrication by Thermal Diffusion on GaSb-VDS-Substrate

The III-V compound semiconductors exhibit the advantage of wide bandgap and high electron mobility, making them appropriate for optoelectronics and microelectronics sector. Vertical directional solidification (VDS) is a technique developed to grow the high quality III-V semiconducting bulk crystals. One of the Sb based III-V materials, Gallium Antimonide (GaSb) was grown by VDS. This direct band gap semiconductor was realized as a ρ-type substrate and thermally diffused in vacuum by Tellurium(Te) ions as n-type dopant to fabricate ρ-n junction. Fabrication of successful ρ-n junction was confirmed by its electrical behaviour. It was later subjected to furnace annealing in vacuum at 200°C and 400°C for dopant to compensate deep in crystal geometry. Rectification characteristics of this junction were distinctly sharp for either biasing. It is revealed that rectification was approaching to optimum ideality factor (1-2) after vacuum furnace annealing at higher temperature. This device exhibits an applicability for NIR sensing close to 1.7µm.

Low current driven blue-violet light-emitting diodes based on p-GaN/i-Ga2O3/n-Ga2O3:Si structure

This paper reports a low current driven LED with p-GaN/i-Ga2O3/n-Ga2O3:Si structure prepared by radio frequency (RF) magnetron sputtering, the driving current of the device is only 0.02 mA. Compared with the reported drive current of the LEDs, the reduction is 100 or even 1000 times. Through the study of its electrical properties, it was found that it had excellent rectification characteristics at different ambient temperatures and the turn-on voltage was about 1.8 V. In addition, the leakage current was as low as 4.30 × 10-8 mA. Through the electroluminescence test, it was found that the device had the function of emitting in the ultraviolet (363 nm) and visible (425 nm) region, which realized the blue-violet luminescence at room temperature. Furthermore, the device had excellent high temperature color stability and ultra-low color temperature of 1924 K. The color coordinate of the device at room temperature was (0.1905,0.0955). A detailed study was conducted on the electroluminescence mechanism of the device through its band structure, and the causes of the luminescence were analyzed through the Gaussian fitting of the EL spectrum.

Fast response self-powered solar-blind UV photodetector based on NiO/Ga2O3 p-n junction

The wide-bandgap semiconductor Ga2O3 exhibits significant promise for application in solar-blind photodetectors (SBPDs) owing to its unique properties. Nevertheless, its practical implementation in photodetectors (PDs) is impeded by the inherent limitations of slow response/recovery times and the intricacies associated with p-type doping, necessitating further scientific research and technological advancements to overcome these challenges. A fast response self-powered SBPD based on p-NiO/n-Ga2O3 heterojunctions constructed by magnetron sputtering method. The effect of different oxygen partial pressures in the sputtering gas on the performance of NiO films and heterojunction PDs was investigated. Through the manipulation of the oxygen partial pressure, p-n junction PDs were successfully prepared, and the optimization of their optical performance was achieved. Irradiated with 254 nm ultraviolet light, the photodetector (PD) with an oxygen partial pressure of 50 % exhibited excellent rectification characteristics, with maximum optical responsivity at zero bias (5.08 mA/W), best detectability (3.19 × 1011 Jones) and fastest response/decay time (62/67 ms). The PDs function autonomously, requiring no external power source, and boast an extremely rapid response time. Our research provides an effective method for the preparation of high-performance heterojunction self-powered SBPD based on Ga2O3 thin films.

Tunable Rectification in 2D Porphyrinic Metal–Organic Framework Nanosheets Molecular Heterojunctions

AbstractAs functional electrical devices advance, new strategies for regulating electrical properties are essential for achieving diverse electrical performance. In this study, molecular heterojunction rectifiers are constructed by connecting porphyrinic 2D metal–organic framework (2D MOF) nanosheets and oligophenylene thiols self‐assembled monolayers (OPT SAMs) within metal electrodes. The rectification characteristics can be tuned by the molecular length of OPT and the coordinated metal atom in the center of 2D MOFs. Specifically, a rectification ratio of more than 1.67 orders of magnitude is achieved in the heterojunction composed of 2D Zn‐TCPP MOF nanosheet (TCCP, tetrakis(4‐carboxyphenyl) porphyrin) and OPT3 SAM. Combining Kelvin probe force microscopy measurements and first‐principles calculations of the 2D MOF nanosheets, it elucidates that the rectification variations come from the adjustment of energy level alignment at OPT SAMs//2D MOF interface, leading to asymmetric charge transport with the voltage polarities. This strategy can be further extended to Cu‐MOF nanosheets, which also exhibit rectification behaviors when placed on OPT2 SAMs. This work provides a universal and flexible strategy for regulating the electrical behaviors of MOFs without the need for specific design and synthesis, paving the way for the development of MOF‐based functional electronic devices.

Fabrication and Characterization of Flexible CuI-Based Photodetectors on Mica Substrates by a Low-Temperature Solution Process

Both CuI and CuI:Zn semiconductor thin films, along with MSM-structured UV photodetectors, were prepared on flexible mica substrates at low temperature (150 °C) by a wet chemical method. The two CuI-based films exhibited a polycrystalline phase with an optical bandgap energy close to 3.0 eV. Hall effect measurements indicated that the CuI thin film sample had p-type conductivity, while the CuI:Zn thin film sample exhibited n-type conductivity, with the latter showing a higher carrier mobility of 14.78 cm2/Vs compared to 7.67 cm2/Vs for the former. The I-V curves of both types of photodetectors showed asymmetric rectification characteristics with rectification ratios at ±3 V of 5.23 and 14.3 for the CuI and CuI:Zn devices, respectively. Flexible CuI:Zn devices exhibited significantly better sensitivity, responsivity, and specific detectivity than CuI devices both before and after static bending tests. It was found that, while the optoelectronic performance of flexible CuI-based photodetectors degraded under tensile stress during static bending tests, they still exhibited good reproducibility and repeatability in their photoresponses.

Hydrogel ionic diode with ultra-high rectification ratio for ionic circuit

Organisms transmit signals through complex ion systems, and signal transmission in artificial electronic circuits mainly depends on electrons. The development of rectifier ionic diode, grounded in ion transport principles, paves ways for artificial bionic circuit and seamless human–machine interaction. Among its pivotal performance indicators, the ion rectification ratio (IR) is of primal importance, facilitating enhanced ion selectivity, bolstered energy efficiency, and robust, high-performing operations. Here, hybrid hydrogel ionic diode based on chitosan (CS) doped with 5,10,15,20-tetrakis(4-aminophenyl)-21,23H-porphyrin (TAPP)/sodium polyacrylate (PAAs) doped with 5,10,15,20-tetrakis(4-sulfonatophenyl)-21,23H-porphyrin (TPPS) was constructed to achieve a high IR. This design achieved a remarkable feat by elevating the IR from 5.57 to an unprecedented 158.64, surpassing previous benchmarks set by hydrogel-based ionic diodes. Moreover, this study emphasizes the selectivity of polyelectrolytes to different porphyrin structures, as well as the charge properties of the groups carried by porphyrins. It delves into the fundamental mechanisms underpinning their interactions, providing a comprehensive understanding of their behavior. In order to demonstrate the excellent rectification characteristics and practical applicability of the CS-TAPP/PAAs-TPPS ionic diode, we successfully integrated it into the full-wave rectification and logic gate system. The full-wave rectifier can convert a 1.2 V sinusoidal voltage input to a 0.8 V full-wave voltage output. This shows the advantages of high IR ionic diodes. It offers insights for the development of high-performance hydrogel-based ionic diodes, and promotes the advancement of novel biomimetic devices and ionic circuits.

2D Gr/WSe2/MoTe2 vertical heterojunction for self-powered photodiode with ultrafast response and high sensitivity

Two-dimensional materials without lattice constraints can be combined into form heterojunctions via van der Waals forces, providing opportunities for the future development of novel high-performance photodetectors. In non-vertical heterojunction devices with long carrier transport channels, SRH recombination due to defect and interface states in the heterojunction and Langevin recombination due to Coulomb interactions induce large amounts of photogenerated carrier recombination, leading to low quantum efficiencies of the heterojunction. At the same time, defect and interface trap states, as well as the long channel of the non-vertical heterojunction device, lead to a slow response speed of the device. In this work, a 2D WSe2/MoTe2 vertical heterojunction photodiode with a transparent graphene top electrode has been designed to simultaneously achieve high sensitivity and fast response speed of photodetectors. Benefiting from the vertical device structure, high-quality interface and low contact resistance, the photogenerated electron-hole pairs can be efficiently separated and transported. The photodiode exhibits remarkable rectification characteristics with a rectification ratio as high as 1.4 × 104, and provides a broadband and self-powered photodetection from the visible to NIR bands (405–1064 nm) with a maximum responsivity of 0.33 A/W at 785 nm. In particular, the photodiode achieves an ultra-fast rise/fall time of 6.49/6.22 μs at 0 V and a further reduction of the response time to 1.68/1.2 μs at a reverse bias of −1 V. This ultra-fast response allows the photodiode to detect switching signals with a cutoff frequency of more than 70 kHz and 200 kHz at 0 V and −1 V, respectively. This work opens up new opportunities for the development of integrated 2D photodetectors with low power consumption, high sensitivity, and high speed.

GaN Nano Air Channel Diodes: Enabling High Rectification Ratio and Neutron Robust Radiation Operation.

Nano air channel transistors (NACTs) provide numerous advantages over traditional silicon devices, including faster switching speeds, higher operating frequencies, and enhanced radiation hardness attributable to the ballistic transport of electrons. In the development of field-emission-based integrated circuits, low-power consumption rectifying nano air channel diodes (NACDs) play a crucial role. However, achieving rectification characteristics in NACDs is challenging due to their structural and material symmetry. This paper proposes a vertical GaN NACD with a consistent nano air channel fabricated using IC-compatible processes. The GaN NACD exhibits an exceptionally low turn-on voltage of 0.3 V while delivering a high output current of 5.02 mA at 3 V. Notably, it demonstrates a high rectification ratio of up to 2.2 × 105, attributing to significant work function disparities within the GaN-Au structure, coupled with the reduction of Au surface roughness to minimize reverse current. Furthermore, the junction-free structure and superior material properties of GaN enable the NACD to be suitable for use in radiation-rich environments. With its potential as a fundamental component of ultrafast and ultrahigh-frequency integrated circuits, this intriguing and cost-effective rectifying diode is anticipated to garner widespread interest within the electronics community.

Spatially selective p-type doping for constructing lateral WS2 p-n homojunction via low-energy nitrogen ion implantation

The construction of lateral p-n junctions is very important and challenging in two-dimensional (2D) semiconductor manufacturing process. Previous researches have demonstrated that vertical p-n junction can be prepared simply by vertical stacking of 2D materials. However, interface pollution and large area scalability are challenges that are difficult to overcome with vertical stacking technology. Constructing 2D lateral p-n homojunction is an effective strategy to address these issues. Spatially selective p-type doping of 2D semiconductors is expected to construct lateral p-n homojunction. In this work, we have developed a low-energy ion implantation system that reduces the implanted energy to 300 eV. Low-energy implantation can form a shallow implantation depth, which is more suitable for modulating the electrical and optical properties of 2D materials. Hence, we utilize low-energy ion implantation to directly dope nitrogen ions into few-layer WS2 and successfully realize a precise regulation for WS2 with its conductivity type transforming from n-type to bipolar or even p-type conduction. Furthermore, the universality of this method is demonstrated by extending it to other 2D semiconductors, including WSe2, SnS2 and MoS2. Based on this method, a lateral WS2 p-n homojunction is fabricated, which exhibits significant rectification characteristics. A photodetector based on p-n junction with photovoltaic effect is also prepared, and the open circuit voltage can reach to 0.39 V. This work provides an effective way for controllable doping of 2D semiconductors.

Ga2O3 Photon‐Controlled Diode for Sensitive DUV/X‐Ray Detection and High‐Resolution Array Imaging Application

AbstractSensitive high‐energy photon detection from UV to X‐ray and high‐resolution array imaging are critical for medical diagnosis, space exploration, and scientific research. The key challenges for high‐performance photodetector and imaging arrays are the effective material and device design strategies for the miniaturization and integration of the device. Here, photon‐controlled diodes (i.e., the detector has rectifying characteristics only under light irradiation) are proposed for high‐resolution and anti‐crosstalk array imaging applications without integrating the switching element. Based on ultra‐wide bandgap semiconductor Ga2O3, the sensitive DUV/X‐ray photon‐controlled diodes are realized by the design of high‐resistance Ga2O3 film and high‐barrier contact. The device exhibits remarkable detection performance, including high photo‐responsivity (168 A W−1) and specific detectivity (1.45 × 1015 Jones) under DUV illumination, as well as a high sensitivity (1.23 × 105 µC Gyair−1 cm−2) under X‐ray light. Moreover, the low dark current and excellent rectification characteristics are obtained. Furthermore, its potential for high‐density and anti‐crosstalk array imaging applications is verified. These results not only bring forth new insights in the implementation of high‐performance DUV/X‐ray photodetector, but also pave a feasible way to realize high pixel density detector array through the simplified fabrication process for high‐resolution imaging applications.

Transport properties of Mn-doped/adsorbed zigzag boron nitride nanoribbon based nanodevices

We are conducting research into the spin transport characteristics of models that are built from zigzag Boron Nitride Nanoribbons (ZBNNRs) that have been doped and adsorbed with Mn. These investigations are made possible by using the non-equilibrium Green’s function (NEGF) formalism in conjunction with Density Functional Theory (DFT). We have scrutinized the electronic structures of six different models, and have chosen two for a deeper exploration of its’ transport characteristics. Our computational findings highlight an unusual occurrence where a Mn atom substitutes a B atom in ZBNNRs, resulting in ZB(Mn)NNRs that exhibit significant Giant Magnetoresistance (GMR) and Rectification ratio (RR) - peaking at 106 and 105 respectively, along with the presence of negative differential conductance (NDC) effects. The detected GMR, NDC, and rectification characteristics in ZB(Mn)NNRs offer an optimistic outlook for the conceptualization of future nanodevices.

Influence of the Dielectric Constant on the Ionic Current Rectification of Bipolar Nanopores.

In this paper, we investigate how the dielectric constant, ϵ, of an electrolyte solvent influences the current rectification characteristics of bipolar nanopores. It is well recognized that bipolar nanopores with two oppositely charged regions rectify current when exposed to an alternating electric potential difference. Here, we consider dilute electrolytes with NaCl only and with a mixture of NaCl and charged nanoparticles. These systems are studied using two levels of description, all-atom explicit water molecular dynamics (MD) simulations and coarse-grained implicit solvent MD simulations. The charge density and electric potential profiles and current-voltage relationship predicted by the implicit solvent simulations with ϵ = 11.3 show good agreement with the predictions from the explicit water simulations. Under nonequilibrium conditions, the predictions of the implicit solvent simulations with a dielectric constant closer to the one of bulk water are significantly different from the predictions obtained with the explicit water model. These findings are closely aligned with experimental data on the dielectric constant of water when confined to nanometric spaces, which suggests that ϵ decreases significantly compared to its value in the bulk. Moreover, the largest electric current rectification is observed in systems containing nanoparticles when ϵ = 78.8. Using enhanced sampling, we have shown that this larger rectification arises from the presence of a significantly deeper minimum in the free energy of the system with a larger ϵ, and when a negative voltage bias is applied. Since implicit solvent models and mean-field continuum theories are often used to design Janus membranes based on bipolar nanopores, this work highlights the importance of properly accounting for the effects of confinement on the dielectric constant of the electrolyte solvent. The results presented here indicate that the dielectric constant in implicit solvent simulations may be used as an adjustable parameter to approximately account for the effects of nanometric confinement on aqueous electrolyte solvents.

The GeSe/SnSe heterojunction photodetector with self-powered characteristics and high infrared response performance

We present a GeSe/SnSe van der Waals heterojunction fabricated using the wet transfer technique. GeSe and SnSe were synthesized via a low-temperature and atmospheric-pressure chemical vapor deposition method. The GeSe/SnSe heterostructure photodetector demonstrates remarkable rectification characteristics, boasting a rectification ratio of 102, along with an exceptionally low dark current, indicating minimal power consumption. Furthermore, it exhibits a broad optical response, spanning from the visible spectrum (450 nm) to the near-infrared (1064 nm). Under 808 nm laser illumination and reverse bias, the device achieves a responsivity of 19.82 A/W, a detectivity of 4.74 × 109 Jones, and an external quantum efficiency of 3048.32%. Notably, the GeSe/SnSe heterojunction photodetector also exhibits self-powered characteristics, with a responsivity of 0.11 mA/W and a detectivity of 5.44 × 106 Jones at zero bias voltage, accompanied by a fast response time of 23/61 ms (rise/fall). These findings underscore the effectiveness of the GeSe/SnSe heterojunction as a strategy for near-infrared photodetectors to simultaneously achieve low power consumption, high photoresponsivity, and self-powered photodetection, which is promising for optoelectronic device applications.

Interface‐Engineering Induced Swift and Controllable Solar‐Blind Photoresponse in Ga2O3/SiC Heterojunction Based on Unconventional Rectification Characteristics

AbstractGa2O3 photodetectors with demonstrated high sensitivity provide a potential subversive scheme for solar‐blind photodetection. However, the planar structure and the relatively slow response speed of the device have restricted the integration and application of Ga2O3 photodetectors. Herein, a narrow SiO2 barrier layer is introduced on the commercial SiC substrate, and a vertical photodetector is realized based on β‐Ga2O3/SiO2/SiC heterostructure with controllable tunneling effect by tailoring the band structure at the interface. The developed device exhibits unconventional rectification characteristics and photoresponse performance in different biasing modes owing to the controllable tunneling effect at the interface. In particular, the photodetector achieves a high responsivity (186.8 A W−1) under solar‐blind illumination at reverse bias, while exhibiting obvious advantages in dark current (3 pA), photo‐to‐dark current ratio (8.8 × 106), linear dynamic range (138.8 dB), and specific detectivity (1.4 × 1015 Jones) at forward bias. The photodetector also demonstrates excellent photoresponse stability after 6 months in air without encapsulation. In addition, an alternating biasing strategy, inspired by its bidirectional operability, is proposed to suppress the persistent photoconductivity effect and increase the decay speed by 1.23 × 105 times. This work provides a referable strategy for the further development of high‐performance Ga2O3‐based photoelectronics.

Electrical characterization of Ag/MoO3−x/p-Si Schottky diodes based on MoO3−x synthesized via sol–gel method: an investigation on frequency and voltage dependence

MoO3−x is a commonly used buffer layer in organic based optoelectronic devices to align energy level between active semiconductor and metal layer. The purpose of this study is to show the effects of the MoO3−x interlayer by comparing with a reference device without MoO3−x interlayer. To evaluate the effect of MoO3−x interlayer synthesized by sol–gel method, basic important parameters such as ideality factor (n), barrier height (∅\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\varnothing$$\\end{document}B), interface states (Nss) and series resistance (Rs) of Ag/MoO3−x/p-Si and Ag/p-Si Schottky diodes were calculated by electrical characterization methods. The current–voltage (I–V) measurements show that the ideality factor for the p-Si/Ag reference diode was decreased from 2.4 to 1.9 while rectification factor increasing 44.6 times using MoO3−x interlayer, and frequency–dependent measurements (C–V–f, G–V–f) were carried out to elucidate this deviation at room temperature for MoO3−x-based diode. From the XPS analysis, it was seen that Mo+6 and Mo+5 oxidation states were intense on the surface of the MoO3−x film, and the Mo+4 oxidation state increased as it went into the bulk. The changes in Rs and Nss due to the energy levels formed by the Mo+6 and Mo+5 oxidation steps at the interface are depicted. In addition, the energy density distribution profile of Nss was obtained using the I–V characteristics for various forward bias voltages range from 2.1 × 1012 to 2.5 × 1012 eV−1 cm−2. Based on the experimental results, the sol–gel synthesized MoO3−x thin film exhibits favorable rectification characteristics and holds promise for application as a Schottky diode.

Adjustable artificial neuron based on vortex magnetic tunnel junction

In this Letter, we demonstrate an adjustable artificial neuron based on vortex magnetic tunnel junction (MTJ). By applying a bias current to vortex MTJ, the device exhibits splendid characteristics of stochastic switching and nonlinear rectification. The stochastic switching probability induced by spin transfer torque as a function of bias current can simulate sigmoid activation functions. The nonlinear spin-torque microwave rectification through injection locking is similar to a ReLU-like activation function. These two behaviors further are used to perform the recognition of handwritten digits in the Mixed National Institute of Standards and Technology database, with a produced accuracy of up to 93.56% and 93.25%, respectively. Our work provides a potential way for the construction of artificial neuron based on vortex MTJ.

Effects of the geometrical parameters on rectification characteristics of convergence angle throttle orifice plates

Under severe operating conditions, the conventional porous plates are rendered ineffective in rectifying the spiral turbulence generated during the steam flow and pressure adjustment process by the primary pressure-reducing valve (PPRV). To address this limitation, an innovative throttle plate with a convergent angle structure is proposed based on the conventional uniformly distributed porous plate in this study. The design aims to rectify the spiral turbulence generated after PPRV and elucidate its formation mechanism. However, there is currently no clear understanding or reliable prediction method for the pressure loss coefficient due to various structural factors influencing the rectification characteristics and pressure drop properties of the converging angle structure throttle orifice plate. This lack of knowledge severely hampers practical applications of this new plate in pressure-reducing desuperheating devices. To address this issue, the present study investigates the underlying mechanisms governing the rectification characteristics and flow resistance properties of a throttle orifice plate with a converging angle structure through experimental investigations and numerical simulations. The focus is on geometric parameters including the converging angle (θ), orifice diameter (d), throttle diameter ratio (β), and plate thickness (h). The findings suggest that the incorporation of a converging angle structure throttle orifice plate is advantageous in achieving effective rectification of spiral turbulence in the secondary pressure pipeline of the pressure-reducing desuperheating device. This modification reduces the required channel distance for enhancing unstable flow, diminishes velocity non-uniformity, and augments the rectification and control capabilities of the medium.