scholarly journals Investigation on Dynamic Characteristics of AlGaN/GaN Lateral Schottky Barrier Diode

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1296
Author(s):  
Haitao Zhang ◽  
Xuanwu Kang ◽  
Yingkui Zheng ◽  
Hao Wu ◽  
Ke Wei ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Dynamic Characteristics ◽  
Performance Optimization ◽  
Computer Aided Design ◽  
Dynamic Performance ◽  
Transient Behavior ◽  
Schottky Barrier Diode ◽  
Carbon Doping ◽  
Current Collapse ◽  
The Impact

This work investigates the transient characteristics of an AlGaN/GaN lateral Schottky barrier diode (SBD) and its recovery process with a dedicated dynamic measurement system. Both static and dynamic characteristics were measured, analyzed with the consideration of acceptor/donor traps in the C-doped buffer and GaN channel, and verified by Silvaco TCAD (technology computer aided design) simulations. The energy band, electric field, and electron concentration were monitored in the transient simulation to study the origin of the current collapse in the SBD. Using the verified model, the impact of carbon doping concentration in the buffer and the thickness of the unintentionally doped (UID) GaN channel in the transient behavior was estimated. Several observations were revealed. Firstly, the traps in the GaN channel and buffer layer have a significant impact on the current collapse of the device. A severe deterioration of current collapse can be observed in the SBDs with increasing density of acceptor-like traps. Secondly, the current collapse increases with the thinner UID GaN channel layer. This well-performed simulation model shows promise to be utilized for the dynamic performance optimization of GaN lateral devices.

scholarly journals A Breakdown Enhanced AlGaN/GaN Schottky Barrier Diode with the T-Anode Position Deep into the Bottom Buffer Layer

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 91 ◽  
Author(s):  
Youlei Sun ◽  
Ying Wang ◽  
Jianxiang Tang ◽  
Wenju Wang ◽  
Yifei Huang ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Buffer Layer ◽  
Computer Aided Design ◽  
Tunneling Current ◽  
Cathode Region ◽  
Schottky Barrier Diode ◽  
Electrical Characteristics ◽  
Edge Termination ◽  
Dimensional Electron Gas ◽  
Aided Design

In this paper, an AlGaN/GaN Schottky barrier diode (SBD) with the T-anode located deep into the bottom buffer layer in combination with field plates (TAI-BBF FPs SBD) is proposed. The electrical characteristics of the proposed structure and the conventional AlGaN/GaN SBD with gated edge termination (GET SBD) were simulated and compared using a Technology Computer Aided Design (TCAD) tool. The results proved that the breakdown voltage (VBK) in the proposed structure was tremendously improved when compared to the GET SBD. This enhancement is attributed to the suppression of the anode tunneling current by the T-anode and the redistribution of the electric field in the anode–cathode region induced by the field plates (FPs). Moreover, the T-anode had a negligible effect on the two-dimensional electron gas (2DEG) in the channel layer, so there is no deterioration in the forward characteristics. After being optimized, the proposed structure exhibited a low turn-on voltage (VT) of 0.53 V and a specific on-resistance (RON,sp) of 0.32 mΩ·cm2, which was similar to the GET SBD. Meanwhile, the TAI-BBF FP SBD with an anode-cathode spacing of 5 μm achieved a VBK of 1252 V, which was enhanced almost six times compared to the GET SBD with a VBK of 213 V.

scholarly journals ANALYSIS OF THE IMPACT OF SPECIAL CONSTRUCTIONS OF GAP SEALS ON THE DYNAMICS OF CENTRIFUGAL MACHINES

ScienceRise ◽  
2020 ◽  
pp. 3-13
Author(s):  
Serhii Shevchenko
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Dynamic Properties ◽  
Dynamic Performance ◽  
Operating Conditions ◽  
Centrifugal Pumps ◽  
Labyrinth Seals ◽  
Research Results ◽  
The Impact ◽  
Technological Product

The object of research: the influence of the design features of special gap seals on the dynamic characteristics of centrifugal machines. Investigated problem: harmonization of the consumption and dynamic characteristics of the seals of the rotors of high-speed machines by applying special design methods. Main scientific results: The mechanism and operating conditions of seals with floating rings are described. It is determined that the most effective from the point of view of dynamic characteristics is the variant of the semi-movable ring. Expressions for determining the conditions of angular and radial immobility of a floating ring are obtained. The design options for deformable gap seals, including deformable floating rings, deformable interwheel seals and seals with an axially movable deformable sleeve, have been investigated. The scope of their application for unique machines with high requirements for tightness and vibration reliability has been determined. Variants of the design of labyrinth seals have been investigated. The analysis shows that the dynamic properties of labyrinth seals significantly depend on the relative position of the ridges. Overlapping ridged seals have the worst dynamic performance of the labyrinth seal designs. The honeycomb seal has more favorable dynamic properties, and the well seal has the best combination of consumption and dynamic characteristics. The dynamic characteristics are especially important for the seals of high-speed rotors of centrifugal machines. The area of practical use of the research results: Enterprises that manufacture centrifugal machines: pumps and compressors. Innovative technological product: a methodology for the selection, design and calculation of special designs of gap seals with optimization of dynamic and flow characteristics. Scope of application of the innovative technological product: The obtained research results will be useful in the design and manufacture of centrifugal pumps and compressors for any parameters.

Simulation Research on Tooth Root Dynamic Stress of Marine Helical Gear Meshing Impact

2013 ◽  
Vol 331 ◽  
pp. 7-10
Author(s):  
Yu Bai Zhang ◽  
Hui Qun Yuan ◽  
Ming Xuan Liang
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Performance Optimization ◽  
Dynamic Stress ◽  
Gear Tooth ◽  
Dynamic Performance ◽  
Element Model ◽  
Helical Gear ◽  
Tooth Root ◽  
The Impact

Finite element model of helical gear meshing of large burden marine is built based on explicit dynamics finite element method, dynamics stress variation of helical gear tooth is simulated under multiple working conditions, research is focused on the impact of changes in working conditions on the dynamic stress of the tooth root. The results show that helical gear pair speed and center distance error have great impact on dynamic stress of tooth root. The results provide reference for dynamic performance optimization of marine gears.

Physics‐based spice model on the dynamic characteristics of silicon carbide Schottky barrier diode

2016 ◽  
Vol 9 (15) ◽  
pp. 2803-2807 ◽  
Author(s):  
Xintian Zhou ◽  
Yan Wang ◽  
Ruifeng Yue ◽  
Gang Dai ◽  
Juntao Li
Keyword(s):  
Silicon Carbide ◽  
Schottky Barrier ◽  
Dynamic Characteristics ◽  
Schottky Barrier Diode ◽  
Spice Model

Bone tissue engineering in the greater omentum with computer-aided design/computer-aided manufacturing scaffolds is enhanced by a periosteum transplant

2020 ◽  
Author(s):  
Hendrik Naujokat ◽  
Klaas Loger ◽  
Juliane Schulz ◽  
Yahya Açil ◽  
Jörg Wiltfang
Keyword(s):  
Bone Formation ◽  
Bone Tissue ◽  
Computer Aided Design ◽  
Bone Tissue Regeneration ◽  
Histological Evaluation ◽  
Greater Omentum ◽  
Collagen Membrane ◽  
Computer Aided ◽  
3D Printed ◽  
The Impact

Aim: This study aimed to evaluate two different vascularized bone flap scaffolds and the impact of two barrier membranes for the reconstruction of critical-size bone defects. Materials & methods: 3D-printed scaffolds of biodegradable calcium phosphate and bioinert titanium were loaded with rhBMP-2 bone marrow aspirate, wrapped by a collagen membrane or a periosteum transplant and implanted into the greater omentum of miniature pigs. Results: Histological evaluation demonstrated significant bone formation within the first 8 weeks in both scaffolds. The periosteum transplant led to enhanced bone formation and a homogenous distribution in the scaffolds. The omentum tissue grew out a robust vascular supply. Conclusion: Endocultivation using 3D-printed scaffolds in the greater omentum is a very promising approach in defect-specific bone tissue regeneration.

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