Normally-off GaN HEMTs with InGaN p-gate cap layer formed by polarization doping

2021 ◽  
Author(s):  
Changkun Zeng ◽  
Weizong Xu ◽  
Yuanyang Xia ◽  
Ke Wang ◽  
Fangfang Ren ◽  
...  
Keyword(s):  
Schottky Contact ◽  
Limiting Factor ◽  
Ingan Layer ◽  
Safe Operation ◽  
High Quality ◽  
Cap Layer ◽  
Doping Technique ◽  
Gan Hemts ◽  
P Type ◽  
Current Blocking

Abstract Narrow gate margin has been the critical limiting factor for the p-gate normally-off GaN HEMTs, imposing significant challenges in both gate-drive design and gate reliability. In this work, by developing dopant-free p-type polarization doping technique in composition-graded InGaN layer, high-quality Schottky contact between the gate metal and cap layer was demonstrated, achieving excellent gate current blocking performance (10-6 mA/mm) after the turning-on of the gate heterojunction structure. Resultantly, normally-off GaN HEMTs with enhanced gate breakdown voltage up to 15.2 V was realized, being especially beneficial for the simplification of gate drive design and the safe operation of gate terminal.

Improving the methods to improve the stability of hydrotechnical structures in Yakutia

2020 ◽  
pp. 37-39
Author(s):  
M LOSKIN
Keyword(s):  
Agricultural Production ◽  
Hydraulic Engineering ◽  
Process Water ◽  
Small Rivers ◽  
Limiting Factor ◽  
Safe Operation ◽  
Central Yakutia ◽  
Agricultural Water Supply ◽  
Temperature Impact ◽  
The Stability

Problems of providing the population and agricultural production by qualitative potable and process water in the Central Yakutia are covered. This territory belongs to the region with acute shortage of water resources which is always a limiting factor of development of agricultural production. For the solution of this burning issue in the 80th years of the last century along the small rivers the systems of hydraulic engineering constructions providing requirements with process water practically of all settlements of the Central Yakutia were constructed. At a construction of all hydraulic engineering buildings the method of construction with preservation of soils of the basis of constructions in a frozen state was applied. When warming the climate which is observed in recent years hydraulic engineering constructions built in regions of a wide spread occurance of breeds of an ice complex and with the considerable volume of water weight, were especially vulnerable. On character and a design they experience continuous threat of damage and demand very attentive relation from the operating organizations. Taking this into account, safe operation of hydraulic engineering constructions in a zone of distribution of permafrost breeds demands new approaches. The article examines features of hydraulic engineering constructions’ operation of agricultural water supply objects in the Central Yakutia. Distinctiveness of hydraulic engineering constructions’ operation is that stability of constructions is intimately bound to temperature impact of a reservoir on ground dams’ body and the basis of constructions. The possibility of inclusion of ways for an intensification of a freezing of constructions in the structure of operational actions is studied. The new method on safe operation of hydraulic engineering constructions as prewinter abatement of the water level in a reservoir accounting volumes and norms of water consumption of the settlement is offered.

Ni∕Al0.2Ga0.8N interfacial reaction and Schottky contact formation using high quality epitaxial layers

2008 ◽  
Vol 103 (5) ◽  
pp. 053708 ◽  
Author(s):  
B. Boudjelida ◽  
I. Gee ◽  
J. Evans-Freeman ◽  
S. A. Clark ◽  
T. G. G. Maffeis ◽  
...  
Keyword(s):  
Interfacial Reaction ◽  
Schottky Contact ◽  
Epitaxial Layers ◽  
High Quality ◽  
Contact Formation

Enhancement-mode AlGaN/GaN HEMTs with thin InGaN cap layer

2008 ◽  
Vol 5 (6) ◽  
pp. 1929-1931 ◽  
Author(s):  
M. Ito ◽  
S. Kishimoto ◽  
F. Nakamura ◽  
T. Mizutani
Keyword(s):  
Enhancement Mode ◽  
Cap Layer ◽  
Gan Hemts

Quantum-Confined Optical Interband Transitions in 5-Doped Doping Superlattices

1989 ◽  
Vol 145 ◽  
Author(s):  
E. F. Schubert ◽  
T. D. Harris ◽  
J. E. Cunningham
Keyword(s):  
Emission Spectra ◽  
Doping Profile ◽  
Luminescence Spectra ◽  
Interband Transitions ◽  
Doping Technique ◽  
Quantum Confined ◽  
P Type ◽  
First Time ◽  
Experimental Absorption ◽  
Good Agreement

AbstractOptical absorption and photoluminescence experiments are performed on GaAs doping superlattices, which have a δ-function-like doping profile of alternating n-type and p-type dopant sheets. Absorption and emission spectra reveal for the first time the clear signature of quantum-confined interband transitions. The peaks of the experimental absorption and luminescence spectra are assigned to calculated energies of quantum-confined transitions with very good agreement. It is shown that the employment of the δ-doping technique results in improved optical properties of doping superlattices.

THE STUDY OF Pd SCHOTTKY CONTACT ON POROUS GaN FOR UV METAL–SEMICONDUCTOR–METAL (MSM) PHOTODETECTORS

2007 ◽  
Vol 16 (04) ◽  
pp. 497-503 ◽  
Author(s):  
L. S. CHUAH ◽  
Z. HASSAN ◽  
H. ABU HASSAN
Keyword(s):  
Molecular Beam Epitaxy ◽  
Tensile Stress ◽  
Molecular Beam ◽  
Schottky Contact ◽  
Nitrogen Plasma ◽  
Porous Sample ◽  
Optical Studies ◽  
High Quality ◽  
Metal Semiconductor Metal ◽  
Msm Photodetectors

High quality unintentionally doped n-type GaN layers were grown on Si (111) substrate using AlN (about 200 nm) as buffer layer by radio frequency (RF) nitrogen plasma-assisted molecular beam epitaxy (MBE). This paper presents the structural and optical studies of porous GaN sample compared to the corresponding as-grown GaN. Metal–semiconductor–metal (MSM) photodiode was fabricated on the samples. For as-grown GaN-based MSM, the detector shows a sharp cut-off wavelength at 362 nm, with a maximum responsivity of 0.254 A/W achieved at 360 nm. For porous GaN MSM detector, a sharp cut-off wavelength at 360 nm with a maximum responsivity of 0.655 A/W was achieved at 359 nm. Both the detectors show a little decrease in responsivity in the UV spectral region. The MSM photodiode based on porous GaN shows enhanced (2×) magnitude of responsivity relative to the as-grown GaN MSM photodiode. Enhancement of responsivity can be attributed to the relaxation of tensile stress and reduction of surface pit density in the porous sample.

scholarly journals The Distribution of Mineral Elements and Protein in Soft Rice was Determined and Analyzed by SEM-EDS Technology

2021 ◽  
pp. 39-50
Author(s):  
Bo Peng ◽  
Xiao-Rui Ma ◽  
Wen-Ting Cui ◽  
Xia-Yu Tian ◽  
Chao Dong ◽  
...  
Keyword(s):  
Amylose Content ◽  
Energy Dispersive Spectrometer ◽  
Sweet Taste ◽  
Mineral Elements ◽  
Limiting Factor ◽  
Rice Seed ◽  
High Quality ◽  
Rice Varieties ◽  
Depth Analysis

Soft rice is a kind of high-quality rice between glutinous rice and sticky rice. It has low amylose content, crystal clear grains, sweet taste, soft glutinous, and is suitable for cooking and porridge. Chalkiness in soft rice is a white opaque part formed by loose endosperm. It is an important character that affects the appearance quality, processing, and cooking quality of rice, and also an important limiting factor that restricts the standard rate of high-quality rice in China. The combination of scanning electron microscope and energy dispersive spectrometer (SEM-EDS) can be used for in-depth analysis of rice, visualization, and quantitative analysis of element distribution in rice. The results showed that there were many kinds of mineral elements in soft rice seeds, among which C and O were the most abundant, followed by N and P, and Mg, Al, P, S, K, Ca, Mn, and Zn were less. The contents of C, N, P, and S in the non-chalky area were significantly higher than those in the chalky area. Especially N and S were the best indicators of protein, and the contents in the chalky area were higher than those in the non-chalky area. It means that the protein content in the chalky part of soft rice seed is less than that in the non-chalky part, which affects the nutritional quality of soft rice. Therefore, the results of this study laid a solid foundation for the in-depth analysis of the distribution of mineral elements and protein in soft rice and their effects on the quality of soft rice, which also provided important information for the cultivation of new high-quality rice varieties in the future.

scholarly journals An analytical model for the current voltage characteristics of GaN-capped AlGaN/GaN and AlInN/GaN HEMTs including thermal and self-heating effects

2020 ◽  
Vol 10 (2) ◽  
pp. 1791
Author(s):  
A. Bellakhdar ◽  
A. Telia ◽  
J. L. Coutaz
Keyword(s):  
Analytical Model ◽  
Drain Current ◽  
High Electron Mobility Transistors ◽  
Published Data ◽  
High Electron ◽  
Self Heating ◽  
Heating Effects ◽  
Cap Layer ◽  
Gan Hemts ◽  
Sheet Density

We present an analytical model for the I-V characteristics of AlGaN/GaN and AlInN/GaN high electron mobility transistors (HEMT). Our study focuses on the influence of a GaN capping layer, and of thermal and self-heating effects. Spontaneous and piezoelectric polarizations at Al (Ga,In)N/GaN and GaN/Al(Ga,In)N interfaces have been incorporated in the analysis. Our model permits to fit several published data. Our results indicate that the GaN cap layer reduces the sheet density of the two-dimensional electron gas (2DEG), leading to a decrease of the drain current, and that n+-doped GaN cap layer provides a higher sheet density than undoped one. In n+GaN/AlInN/GaN HEMTs, the sheet carrier concentration is higher than in n+GaN/AlGaN/GaN HEMTs, due to the higher spontaneous polarization charge and conduction band discontinuity at the substrate/barrier layer interface.

Temperature dependent electrical properties of rare-earth metal Er Schottky contact on p-type InP

2013 ◽  
Author(s):  
L. Dasaradha Rao ◽  
N. Ramesha Reddy ◽  
A. Ashok Kumar ◽  
V. Rajagopal Reddy
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Rare Earth Metal ◽  
Schottky Contact ◽  
Earth Metal ◽  
Temperature Dependent ◽  
P Type

scholarly journals Donor/Acceptor Photovoltaic Cells Fabricated on p-Doped Organic Single-Crystal Substrates

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2068 ◽  
Author(s):  
Yusuke Yabara ◽  
Seiichiro Izawa ◽  
Masahiro Hiramoto
Keyword(s):  
Single Crystal ◽  
Photovoltaic Cells ◽  
Photocurrent Density ◽  
Iron Chloride ◽  
Single Crystal Substrate ◽  
Organic Single Crystal ◽  
Crystal Substrate ◽  
Donor Acceptor ◽  
Doping Technique ◽  
P Type

In this study, the operation of donor/acceptor photovoltaic cells fabricated on homoepitaxially grown p-doped rubrene single-crystal substrates is demonstrated. The photocurrent density is dominated by the sheet conductivity (σ□) of the p-type single-crystal layer doped to 100 ppm with an iron chloride (Fe2Cl6) acceptor. A 65 μm thick p-type rubrene single-crystal substrate is expected to be required for a photocurrent density of 20 mA·cm−2. An entire bulk doping technique for rubrene single crystals is indispensable for the fabrication of practical organic single-crystal solar cells.

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