scholarly journals GaN-Based LEDs Grown on Graphene-Covered SiO2/Si (100) Substrate

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 787
Author(s):  
Wurui Song ◽  
Fang Ren ◽  
Yunyu Wang ◽  
Yue Yin ◽  
Shuo Zhang ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Large Scale ◽  
Growth Parameters ◽  
Low Cost ◽  
Buffer Layers ◽  
Oxide Semiconductor ◽  
Organic Chemical ◽  
Amorphous Sio2 ◽  
Axis Orientation ◽  
Amorphous Substrates

The growth of nitride on large-size and low-cost amorphous substrates has attracted considerable attention for applications in large-scale optoelectronic devices. In this paper, we reported the growth of GaN-based light-emitting diodes (LEDs) on amorphous SiO2 substrate with the use of nanorods and graphene buffer layers by metal organic chemical vapor deposition (MOCVD). The effect of different growth parameters on the morphology and vertical-to-lateral aspect ratio of nanorods was discussed by analyzing growth kinetics. Furthermore, we tuned nanorod coalescence to obtain continuous GaN films with a blue-LED structure by adjusting growth conditions. The GaN films exhibited a hexagonal wurtzite structure and aligned c-axis orientation demonstrated by X-ray diffractometer (XRD), Raman, and transmission electron microscopy (TEM) results. Finally, five-pair InGaN/GaN multi-quantum-wells (MQWs) were grown. The photoluminescence (PL) showed an intense emission peak at 475 nm, and the current–voltage (I-V) curve shows a rectifying behavior with a turn-on voltage of 5.7 V. This work provides a promising fabrication method for the large-area and low-cost GaN-based devices on amorphous substrates and opens up the further possibility of nitride integration with Si (100) complementary metal oxide semiconductor (CMOS) electronics.

scholarly journals Process Design Kit and Design Automation for Flexible Hybrid Electronics

2019 ◽  
Vol 16 (3) ◽  
pp. 117-123
Author(s):  
Tsung-Ching Huang ◽  
Ting Lei ◽  
Leilai Shao ◽  
Sridhar Sivapurapu ◽  
Madhavan Swaminathan ◽  
...  
Keyword(s):  
Process Design ◽  
Design Automation ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Thin Film Transistor ◽  
Solution Process ◽  
Oxide Semiconductor ◽  
Wearable Electronics ◽  
Wide Range

Abstract High-performance low-cost flexible hybrid electronics (FHE) are desirable for applications such as internet of things and wearable electronics. Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for high-performance FHE because of its high carrier mobility, superior mechanical flexibility, and material compatibility with low-cost printing and solution processes. Flexible sensors and peripheral CNT-TFT circuits, such as decoders, drivers, and sense amplifiers, can be printed and hybrid-integrated with thinned (<50 μm) silicon chips on soft, thin, and flexible substrates for a wide range of applications, from flexible displays to wearable medical devices. Here, we report (1) a process design kit (PDK) to enable FHE design automation for large-scale FHE circuits and (2) solution process-proven intellectual property blocks for TFT circuits design, including Pseudo-Complementary Metal-Oxide-Semiconductor (Pseudo-CMOS) flexible digital logic and analog amplifiers. The FHE-PDK is fully compatible with popular silicon design tools for design and simulation of hybrid-integrated flexible circuits.

scholarly journals Lead Selenide Polycrystalline Coatings Sensitized Using Diffusion and Ion Beam Methods for Uncooled Mid-Infrared Photodetection

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 444 ◽  
Author(s):  
Hao Yang ◽  
Xiaojiang Li ◽  
Guodong Wang ◽  
Jianbang Zheng
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Low Cost ◽  
Ion Beam ◽  
Lead Selenide ◽  
Cmos Technology ◽  
Oxide Semiconductor ◽  
Recombination Suppression ◽  
Mid Infrared ◽  
Physical Effects

Polycrystalline lead selenide material that is processed after a sensitization technology offers the additional physical effects of carrier recombination suppression and carrier transport manipulation, making it sufficiently sensitive to mid-infrared radiation at room temperature. Low-cost and large-scale integration with existing electronic platforms such as complementary metal–oxide–semiconductor (CMOS) technology and multi-pixel readout electronics enable a photodetector based on polycrystalline lead selenide coating to work in high-speed, low-cost, and low-power consumption applications. It also shows huge potential to compound with other materials or structures, such as the metasurface for novel optoelectronic devices and more marvelous properties. Here, we provide an overview and evaluation of the preparations, physical effects, properties, and potential applications, as well as the optoelectronic enhancement mechanism, of lead selenide polycrystalline coatings.

scholarly journals A Smart Floating Gate Transistor with Two Control Gates for Active Noise Control

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 722
Author(s):  
Mao ◽  
Yang ◽  
Ma ◽  
Yan ◽  
Zhang
Keyword(s):  
Large Scale ◽  
Noise Control ◽  
Low Cost ◽  
Active Noise Control ◽  
Complementary Metal Oxide Semiconductor ◽  
Floating Gate ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Active Noise ◽  
Floating Gate Transistor

A smart floating gate transistor with two control gates was proposed for active noise control in bioelectrical signal measurement. The device, which is low cost and capable of large-scale integration, was implemented in a standard single-poly complementary metal–oxide–semiconductor (CMOS) process. A model of the device was developed to demonstrate the working principle. Theoretical analysis and simulation results proved the superposition of the two control gates. A series of test experiments were carried out and the results showed that the device was in accordance with the basic electrical characteristics of a floating gate transistor, including the current–voltage (I–V) characteristics and the threshold characteristics observed on the two control gates. Based on the source follower circuit, the experimental results proved that the device can reduce interference by more than 29 dB, which demonstrates the feasibility of the proposed device for active noise control.

Liquid Source Mocvd of High Quality Yba2Cu3O7−x Films on Polycrystalline And Amorphous Substrates

1995 ◽  
Vol 415 ◽  
Author(s):  
D.B. Studebaker ◽  
G. Doubinina ◽  
J. Zhang ◽  
Y.Y. Wang ◽  
V.P. Dravid ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Fused Silica ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Polycrystalline Alumina ◽  
Silica Substrate ◽  
Liquid Source ◽  
Amorphous Substrates ◽  
Metal Organic ◽  
Steel Substrates

ABSTRACTHigh temperature superconducting Yba2Cu3O7−x films were grown by liquid delivery metal-organic chemical vapor deposition (LDMOCVD) on silver-coated stainless steel substrates. The films are c-axis oriented, and exhibit a very low surface resistance of 110 μΩ at 77 K and 3 GHz. A two-step LDMOCVD method for growth of oriented (200) CeO2 films on amorphous substrates was also developed. Films of CeO2 for YBCO buffer layers were grown on fused silica (SiO2), polycrystalline alumina (Al2O3), and sapphire (A12O3). A highly c-axis oriented film of YBCO was grown on a fused silica substrate with a CeO2 buffer layer.

scholarly journals An ISFET Microarray Sensor System for Detecting the DNA Base Pairing

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 731
Author(s):  
Peng Sun ◽  
Yongxin Cong ◽  
Ming Xu ◽  
Huaqing Si ◽  
Dan Zhao ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Large Scale ◽  
Ph Value ◽  
Low Cost ◽  
Complementary Metal Oxide Semiconductor ◽  
Fluorescent Labeling ◽  
Oxide Semiconductor ◽  
Sensor System ◽  
Base Pairing ◽  
Dna Base

Deoxyribonucleic acid (DNA) sequencing technology provides important data for the disclosure of genetic information and plays an important role in gene diagnosis and gene therapy. Conventional sequencing devices are expensive and require large and bulky optical structures and additional fluorescent labeling steps. Sequencing equipment based on a semiconductor chip has the advantages of fast sequencing speed, low cost and small size. The detection of DNA base pairing is the most important step in gene sequencing. In this study, a large-scale ion-sensitive field-effect transistor (ISFET) array chip with more than 13 million sensitive units is successfully designed for detecting the DNA base pairing. DNA base pairing is successfully detected by the sensor system, which includes the ISFET microarray chip, microfluidic system, and test platform. The chip achieves a high resolution of at least 0.5 mV, thus enabling the recognition of the change of 0.01 pH value. This complementary metal-oxide semiconductor (CMOS) compatible and cost-efficient sensor array chip, together with other specially designed components, can form a complete DNA sequencing system with potential application in the molecular biology fields.

Research Progress on Improving the Photovoltaic Performance of Polymer Solar Cells

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Yanmin Wang
Keyword(s):  
Solar Cells ◽  
Large Scale ◽  
Polymer Solar Cells ◽  
Low Cost ◽  
Photovoltaic Performance ◽  
Buffer Layers ◽  
Polymer Materials ◽  
Research Progress ◽  
Future Research ◽  
Photovoltaic Properties

Although polymer materials possess the advantages such as low cost and easy fabrication of flexible and large-scale film for the application in photovoltaic devices, the performance of polymer-based solar cells, especially energy conversion efficiency is inferior to their inorganic counterpart due to the shorter charge diffusion length caused by the comparatively lower electric field between the electrodes. This paper reviewed the strategies to improve their photovoltaic properties mainly concentrated on modifying the polymer materials and ameliorating the device configuration. First, polythiophene (PT), poly(phenylene vinylene) (PPV), polyfullerene, and other novel polymer materials were introduced and the effective ways to modify their derivatives with more advantages were described in detail, for instance, copolymerization, incorporating additives and dyes, etc. Furthermore, the content of ameliorating the device configuration encompassed on inverted architecture, tandem structure, the introduction of buffer layers, thermal annealing, and the integration of optimized conditions. Finally, the effects of the improvement methods were concisely summarized, and the perspectives of the future research were put forth.

scholarly journals One-Dimensional Metal Oxide Nanostructures for Chemical Sensors

2021 ◽  
Author(s):  
Esther Hontañón ◽  
Stella Vallejos
Keyword(s):  
Metal Oxide ◽  
Chemical Sensors ◽  
Large Scale ◽  
Low Cost ◽  
Cost Effective ◽  
Oxide Semiconductor ◽  
One Dimensional ◽  
Metal Oxide Nanostructures ◽  
Art Research ◽  
A Charge

The fabrication of chemical sensors based on one-dimensional (1D) metal oxide semiconductor (MOS) nanostructures with tailored geometries has rapidly advanced in the last two decades. Chemical sensitive 1D MOS nanostructures are usually configured as resistors whose conduction is altered by a charge-transfer process or as field-effect transistors (FET) whose properties are controlled by applying appropriate potentials to the gate. This chapter reviews the state-of-the-art research on chemical sensors based on 1D MOS nanostructures of the resistive and FET types. The chapter begins with a survey of the MOS and their 1D nanostructures with the greatest potential for use in the next generation of chemical sensors, which will be of very small size, low-power consumption, low-cost, and superior sensing performance compared to present chemical sensors on the market. There follows a description of the 1D MOS nanostructures, including composite and hybrid structures, and their synthesis techniques. And subsequently a presentation of the architectures of the current resistive and FET sensors, and the methods to integrate the 1D MOS nanostructures into them on a large scale and in a cost-effective manner. The chapter concludes with an outlook of the challenges facing the chemical sensors based on 1D MOS nanostructures if their massive use in sensor networks becomes a reality.

Influence of the Strain of AlN Buffer Layer on the Strain Evolution of GaN Epilayer Grown on 3-in 6H-SiC Substrate

2011 ◽  
Vol 335-336 ◽  
pp. 1242-1245
Author(s):  
Yu Long Fang ◽  
Jia Yun Yin ◽  
Zhi Hong Feng
Keyword(s):  
Large Scale ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Double Crystal ◽  
Strain Evolution ◽  
Scattering Spectra ◽  
Metal Organic ◽  
Raman Scattering Spectra ◽  
Aln Buffer

The influence of the strain of AlN buffer layers on the strain evolution of GaN epilayers grown on 3-in 6H-SiC substrates by metal-organic chemical vapor deposition was investigated by double-crystal X-ray diffractometry, and Raman scattering spectra. It was found that the tensile strain of the GaN epilayers mainly decreases with the strain of the AlN buffer layers varied from tensile to compressive. A model based on the strain evolution during the epitaxial growth is proposed to provide a valuable reference for the massive production of large scale and high quality GaN epilayers.

Selective Area Growth of GaN Nano Islands by Metal Organic Chemical Vapor Deposition: Experiments and Computer Simulations

2006 ◽  
Vol 955 ◽  
Author(s):  
Anilkumar Chandolu ◽  
Gela D Kipshidze ◽  
Sergey A Nikishin ◽  
Lu Tian ◽  
Song Daoying ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Surface Diffusion ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Multiple Quantum ◽  
Mocvd Growth ◽  
Narrow Line Width ◽  
Metal Organic ◽  
And Control

ABSTRACTWe report the properties of GaN islands selectively grown by MOCVD on (0001) GaN/sapphire templates and on bare (0001) sapphire substrates. The approach allows us to grow GaN crystals with control over size and density through optical (micro-scale) and e-beam (nano-scale) lithography, and control over shape through MOCVD growth parameters. We have obtained complete pyramidal and prismatic hexagonal GaN islands. The growth characteristics are found to be very different from what we obtain for epitaxial layers, an effect which is attributed to micro/nanoloading and surface diffusion of source materials on the hard mask. From the dependence of growth rate of the pyramids with pitch we evaluate Ga surface diffusion length of ∼ 10 μm over SiO2 mask. We present a growth model based on diffusion and discuss the results of modeling with experimental data. Using micro-Raman spectroscopy the stress in pyramidal and prismatic islands was evaluated to be 20 MPa and 85 MPa, respectively. This implies that the selectively grown islands are relatively more relaxed compared to similar thickness of uniform layers. Micro catholdoluminescence (CL) shows a narrow line width and a better quality of GaN nano islands grown on e-beam lithography patterned templates. The GaN islands, of varying shapes, were overgrown with InGaN multiple quantum wells, which showed a few times stronger micro-CL emission than from GaN.

scholarly journals Enhanced Electrical Properties of Alkali-Doped ZnO Thin Films with Chemical Process

Solar ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 30-40
Author(s):  
Jaime G. Cuadra ◽  
Samuel Porcar ◽  
Diego Fraga ◽  
Teodora Stoyanova-Lyubenova ◽  
Juan B. Carda
Keyword(s):  
Electrical Properties ◽  
Large Scale ◽  
Low Cost ◽  
Light Trapping ◽  
Hexagonal Phase ◽  
Optical Transmittance ◽  
Zno Films ◽  
Spray Pyrolysis Method ◽  
Axis Orientation ◽  
Doped Zno

Doped ZnO are among the most attractive transparent conductive oxides for solar cells because they are relatively cheap, can be textured for light trapping, and readily produced for large-scale coatings. Here, we focus on the development of alternative Na and K-doped ZnO prepared by an easy low-cost spray pyrolysis method for conducting oxide application. To enhance the electrical properties of zinc oxide, alkali-doped Zn1−x MxO (x = 0.03) solid solutions were investigated. The resulting layers crystallize in a single hexagonal phase of wurtzite structure with preferred c-axis orientation along a (002) crystal plane. Dense, well attached to the substrate, homogeneous and highly transparent layers were obtained with great optical transmittance higher than 80%. The optical energy band gap of doped ZnO films increase from 3.27 to 3.29 eV by doping with Na and K, respectively. The electrical resistivity of the undoped ZnO could be decreased from 1.03 × 10−1 Ω.cm to 5.64 × 10−2 Ω.cm (K-doped) and 3.18 × 10−2 (Na-doped), respectively. Lastly, the carrier concentrations increased from 5.17 × 1017 (undoped ZnO) to 1 × 1018 (doped ZnO).

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