检索结果-内蒙古大学图书馆

2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)

作者： Vikas Kumar Ammar Nayfeh Department of Electrical Engineering and Computer Science (EECS) Masdar Institute of Science and Technology Abu Dhabi United Arab Emirates

ISBN: (纸本)9781479943975

This study investigates the performance of impact ionization (ii) enhanced thin film c-si solar cells using technology computer aided design (tcad) simulations. The effect of ii concerning the electrical and optical properties of the c-si solar cell is carried out. We introduce p + pocket with a high doping density of the magnitude > 10 18 cm -3 to increase the electric field near the junction to values near 1 mv/cm. Using this structure the effect of ii on key solar cell parameters like J sc , V oc , efficiency and quantum efficiency are investigated. The simulation results show that high doping density of p + pocket enhances the current density without affecting the voltage. In addition, by varying the doping concentration of the p + pocket from 10 18 cm -3 to 9×10 18 cm -3 the current density increases from 18 mA/cm 2 to 32 mA/cm 2 . In addition simulation results also show that internal quantum efficiency (iqe) can reach up to 1.89 with very highly doped p+ pocket (9×10 18 cm -3 ).

关键词： Photovoltaic cells Doping Semiconductor process modeling Impact ionization current density Silicon Electric fields

来源：评论

学校读者我要写书评

暂无评论

current density of carriers and emission rate in zinc selenide LED

Current density of carriers and emission rate in zinc seleni...

引用

International Conference on Electronic design (ICED)

作者： U.K. Sahbudin M.H.A. Wahid P. Poopalan N.A.M. Ahmad Hambali M.M. Shahimin S.N. Ariffin N.N.A. Saidi M.A.M. Azidin Semiconductor Photonics & Integrated Lightwave Systems (SPILS) School of Microelectronic Engineering Universiti Malaysia Perlis Perlis Malaysia Semiconductor Photonics & Integrated Lightwave Systems (SPILS) School of Microelectronic Engineering Universiti Malaysia Perlis Arau Perlis MY Faculty of Engineering National Defence University of Malaysia (UPNM) Kuala Lumpur

ISBN: (纸本)9781509021611

This work is based on the development of LED using a circular chip of ZnSe. Proper analyses of the proposed LED are performed by adding optical transition and nonradiative recombination processes. The voltage applied to the ZnSe LED ranges from 0 V to 3.5 V. The current-voltage characteristic and the flow of current density are obtained. At 2.5 V, the carriers move towards n-contact hence reduces the internal quantum efficiency. The carriers are observed to drift in opposite direction of the electric field until recorded voltage of 3.5 V where both carriers in line with the electric field. The emission at low voltage in p-layer is localized and caused the efficiency to reduce considerably.

关键词： Light emitting diodes Charge carrier processes ii-VI semiconductor materials Zinc compounds current density Radiative recombination

来源：评论

学校读者我要写书评

暂无评论

Graphene-Coated Microring Resonator (MRR)-based Gas Sensor using Novel Intensity-Level Detection for low-cost, rapid, and label-free Sensing: Preliminary Simulated Results

Graphene-Coated Microring Resonator (MRR)-based Gas Sensor u...

引用

URSI Atlantic Radio Science Conference (URSI AT-RASC)

作者： Kent C. Soria Benjamin B. Dingel Jezlor Villarde Ramon C. Lapina Cindy Lisa Esporlas Luther Villacruz Kryss Urbano Francesca Palabrica Clint Dominic Bennett Department of Physics School of Science and Engineering Ateneo de Manila University Quezon City Philippines Nasfine Photonics Inc. Painted Post NY USA

ISBN: (数字)9789463968102

ISBN: (纸本)9798350360257

Almost all current microring resonator (MRR) based sensors rely on a wavelength shift detection scheme. This involves (i) expensive tunable lasers as an input source and (ii) optical spectrum analyzers as a detector, which leads to overall bulky configuration, high cost, and complex arrangement. Here, we propose a low-cost, tapered waveguide MRR-based gas sensor that uses a simple intensity-level detection method. It employs (1) a low-cost laser source and (2) a photodetector. The MRR is coated with graphene to detect the specific target element. This design can significantly reduce the overall cost and complexity of the sensing system.

关键词： Costs Graphene optical device fabrication optical resonators Waveguide lasers Photodetectors Safety

来源：评论

学校读者我要写书评

暂无评论

In-channel modifications for improved optical detection of phosphate in a microfluidic chip design

In-channel modifications for improved optical detection of p...

引用

OCEANS - Europe

作者： Joyce O’Grady Nigel Kent Ivan Maguire Philip McGinnity Eleanor Jennings Fiona Regan DCU Water Institute School of Chemical Sciences Dublin City University Dublin Ireland engCORE School of Aerospace Mechanical and Electronic Engineering Carlow Institute of Technology Carlow Ireland School of Biological Earth and Environmental Sciences University College Cork Cork Ireland line 2 Centre for Freshwater Studies and Department of Applied Sciences Dundalk Institute of Technology Dundalk Ireland

Recent developments in the area of low cost optical analysers has enabled rapid, reliable and robust analysis of water nutrient levels, such as phosphate, in water systems. Herein, describes an enhancement study of a previously demonstrated lab- on-a-disc (LOAD) centrifugal microfluidic device for the detection of phosphate in freshwater. The LOAD device utilizes a microfluidic sample processing to enable high precision metering and reagent mixing, followed by colorimetric analysis (at 880 nm) of the resultant complex. A customisable and complementary, in-house analysis system was also developed to enhance user interaction and enable rapid analysis. This analysis system delivers both disc centrifugation and automated colourimetric detection of the LOAD device, with recording of data transmitted via PC interface. The aim of this study is to maintain the same level of sensitivity of the current[1] system with a reduced pathlength. The limit of detection (LOD) and limit of quantification (LOQ) for this new revised system are as follows: The blackened chip obtained the best sensitivity with an LOD and LOQ of 6 and 19 μg L -1 respectively, followed by the P80 roughened chip which achieved 13 and 38 μg L -1 , these results will be discussed further in this *** previously demonstrated microfluidic platform demonstrated an optical path length detection of 75 mm for optimal detectability, resulting in low quantity of sample testing per disc. This work details the optimisation of the disc design through a reduction of path length, therefore increasing the number of test replications on-disc by two-fold and a reduction in reagent consumption, whilst maintaining the same sensitivity using photo-enhancement techniques. The photo-enhancement techniques described in this paper utilize detection channel surface modifications, e.g. coatings and refractive index modification. These assist in significantly improving the signal-to-noise (S/N) with increased transmittance, hence

关键词： optical sensors Microfluidics Chemicals Sensitivity Paints Detectors Light emitting diodes

来源：评论

学校读者我要写书评

暂无评论

Coronary artery segmentation from intravascular optical coherence tomography using deep capsules

arXiv

引用

arXiv 2020年

作者： Balaji, Arjun Kelsey, Lachlan J. Majeed, Kamran Schultz, Carl J. Doyle, Barry J. Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and Centre for Medical Research The University of Western Australia Perth Australia School of Engineering The University of Western Australia Perth Australia Department of Cardiology Royal Perth Hospital Perth Australia School of Medicine The University of Western Australia Perth Australia University of Ottawa Heart Institute OttawaON Canada Australian Research Council Centre for Personalised Therapeutics Technologies Australia British Heart Foundation Centre for Cardiovascular Science The University of Edinburgh United Kingdom

The segmentation and analysis of coronary arteries from intravascular optical coherence tomography (IVOCT) is an important aspect of diagnosing and managing coronary artery disease. current image processing methods are hindered by the time needed to generate expert-labelled datasets and the potential for bias during the analysis. Therefore, automated, robust, unbiased and timely geometry extraction from IVOCT, using image processing, would be beneficial to clinicians. With clinical application in mind, we aim to develop a model with a small memory footprint that is fast at inference time without sacrificing segmentation quality. Using a large IVOCT dataset of 12,011 expert-labelled images from 22 patients, we construct a new deep learning method based on capsules which automatically produces lumen segmentations. Our dataset contains images with both blood and light artefacts (22.8%), as well as metallic (23.1%) and bioresorbable stents (2.5%). We split the dataset into a training (70%), validation (20%) and test (10%) set and rigorously investigate design variations with respect to upsampling regimes and input selection. We show that our developments lead to a model, DeepCap, that is on par with state-of-the-art machine learning methods in terms of segmentation quality and robustness, while using as little as 12% of the parameters. This enables DeepCap to have per image inference times up to 70% faster on GPU and up to 95% faster on CPU compared to other state-of-the-art models. DeepCap is a robust automated segmentation tool that can aid clinicians to extract unbiased geometrical data from IVOCT. © 2020, CC BY.

关键词： optical tomography

来源：评论

学校读者我要写书评

暂无评论

Deep UV LEDs

Deep UV LEDs

引用

International Symposium Semiconductor Device Research (ISDRS)

作者： Remis Gaska Sensor Electronic Technology Inc. USA

Summary form only given. iiI-Nitride semiconductor-based Deep UV (DUV) LEDs are emerging as an enabling technology for diverse military, homeland security, industrial and commercial markets and space exploration. current technology allows to fabricate AlGaN-based DUV LEDs with wall-plug efficiency (WPE) between 1-2%, which is substantially lower that WPE for visible and near UV LEDs. Significant R&D efforts are under way, including DARPA's “Compact Mid-Ultraviolet Technology” (CMUVT) program, to improve materials quality, device fabrication and light extraction to increase WPE of DUV LEDs by more than order of magnitude. We will present an overview of our latest developments in the development of DUV LED technology with the main focus on novel device designs to increase quantum efficiency and improve UV light extraction and reliability of devices emitting in the range of 230 nm 340 nm. Novel QW design has been implemented to suppress polarization effects and phonon engineering approach to increase electron trapping in the active layer of the devices. Very narrow (; 0.4 eV) quantum wells were used to suppress Stark effect and increase radiative recombination. Active region of DUV LEDs was embedded inside a deep potential well (larger than the energy of optical phonon) to increase electron-LO phonon scattering and accelerate cooling of hot injected electrons. This allowed us to increase electron capture into the active region without using conventional electron "blocking layer" commonly used in visible LEDs We developed and incorporated UV-transparent p-type cladding layers to reduce optical losses due to strong absorption in the top p-AlGaN cladding layer and p+-AlGaN or p+-GaN contact layers. Combination with new type of ohmic contact reflecting in DUV spectral range allowed us to significantly improve light extraction and increase output power of DUV LEDs by 2 times in the range of 275 nm - 300 nm and 2.5 times in the range from 310 nm to 340 nm. Improved quality o

关键词： Light emitting diodes Phonons Semiconductor device reliability optical reflection optical device fabrication

来源：评论

学校读者我要写书评

暂无评论

高性能锑化物超晶格中红外探测器研究进展(特邀)

引用

红外与激光工程 2022年第3期51卷 22-31页

作者：郝宏玥吴东海徐应强王国伟蒋洞微牛智川中国科学院大学半导体研究所北京100083

中红外探测技术作为一种重要的被动探测手段,在各个领域都有着非常重要的作用。其中,以InAs/InAsSb超晶格材料为基础的无Ga型Sb化物ii类超晶格探测器,由于去除了Ga原子的缺陷,具有更高的少子寿命,有利于提高探测器性能。此外,使用光子... 详细信息

中红外探测技术作为一种重要的被动探测手段,在各个领域都有着非常重要的作用。其中,以InAs/InAsSb超晶格材料为基础的无Ga型Sb化物ii类超晶格探测器,由于去除了Ga原子的缺陷,具有更高的少子寿命,有利于提高探测器性能。此外,使用光子晶体结构,进行表面光学性能调控,可以提高器件的响应度,从而降低材料吸收区厚度,降低器件暗电流。暗电流的降低和响应度的提升,进一步优化了探测器的性能,进而提高器件工作温度,进一步降低探测系统的体积、重量和功耗。研究表明:使用光子晶体结构可以在不改变外延材料结构的前提下,提高器件量子效率,实现响应光谱的展宽,在实际应用中具有重要的意义。文中综述和讨论了InAs/InAsSb超晶格探测器和光子晶体结构探测器材料生长、结构设计的主要技术问题,详细介绍了两种提高中红外探测器性能的方案及国内外的研究进展。

关键词：锑化物中红外探测技术高工作温度 InAs/InAsSb二类超晶格光子晶体

来源：评论

学校读者我要写书评

暂无评论

From compressive sampling to compressive tasking:retrieving semantics in compressed domain with low bandwidth

引用

PhotoniX 2022年第1期3卷 177-198页

作者： Zhihong Zhang Bo Zhang Xin Yuan Siming Zheng Xiongfei Su Jinli Suo David J.Brady Qionghai Dai Department of Automation Tsinghua University100084 BeijingChina Research Center for Industries of the Future and School of Engineering Westlake University310024 HangzhouChina Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province Westlake University310024 HangzhouChina Computer Network Information Center Chinese Academy of Sciences100190 BeijingChina University of Chinese Academy of Sciences 100049 BeijingChina Wyant College of Optical Sciences University of ArizonaAZ 85721 TucsonUSA

High-throughput imaging is highly desirable in intelligent analysis of computer vision *** conventional design,throughput is limited by the separation between physical image capture and digital post *** imaging increases throughput by mixing analog and digital processing through the image capture ***,recent advances of computational imaging focus on the“compressive sampling”,this precludes the wide applications in practical *** paper presents a systematic analysis of the next step for computational imaging built on snapshot compressive imaging(SCI)and semantic computer vision(SCV)tasks,which have independently emerged over the past decade as basic computational imaging *** is a physical layer process that maximizes information capacity per sample while minimizing system size,power and *** is an abstraction layer process that analyzes image data as objects and features,rather than simple pixel *** current practice,SCI and SCV are independent and *** concatenated pipeline results in the following problems:i)a large amount of resources are spent on task-irrelevant computation and transmission,ii)the sampling and design efficiency of SCI is attenuated,and iii)the final performance of SCV is limited by the reconstruction errors of *** these concerns in mind,this paper takes one step further aiming to bridge the gap between SCI and SCV to take full advantage of both *** reviewing the current status of SCI,we propose a novel joint framework by conducting SCV on raw measurements captured by SCI to select the region of interest,and then perform reconstruction on these regions to speed up processing *** use our recently built SCI prototype to verify the *** results are presented and the prospects for a joint SCI and SCV regime are *** conducting computer vision tasks in the compressed domain,we envision that a new era of snapshot compressive imaging wit

关键词： Snapshot compressive imaging Semantic computer vision Computational imaging Deep learning

来源：评论

学校读者我要写书评

暂无评论

New developments in mid-infrared Sb-based lasers

引用

Journal De Physique. IV : JP 1999年第2期9卷 Pr2-79-Pr2-96页

作者： Joullié, A. Ctr. Electronique M. UMR 5507 du CNRS Sciences et Techniques du Laguedoc Case 067 37095 Montpellier Cedex 05 France

A number of different approaches are being investigated to obtain high-performance mid-infrared (2-5 μm) diode lasers for applications such as infrared lidar, remote sensing and environmental monitoring. They include laser heterostructures based on interband transitions in quantum-well or superlattice active region, and quantum cascade structures based on unipolar intersubband transitions. The Sb-containing structures, employing GaSb, InAs, AlSb and related alloys, are focusing actually much attention. Significant improvements in the molecular beam epitaxy of these alloys make possible now the growth of laser antimonide structures of high structural quality. Excellent performances have been reported at ≈ 2 μm from GaInAsSb/AlGaAsSb and at ≈ 3.5 μm from InAsSb/InAlAsSb type-I quantum-well diode lasers. Type-ii (staggered alignment) GaInAsSb/GaSb and type-iiI (broken gap alignment) InAs/Ga(In)Sb strained multiquantum-well lasers are promising material systems for mid-infrared sources, due to their large conduction and valence band offsets, the potential of Auger process suppression and the enhancement of the electron-hole optical coupling by wave function engineering. Besides high performance interband quantum cascade lasers operating at room temperature with negligible current leakage and high output power can be designed from Sb-containing type-iiI structures.

关键词： Quantum well lasers

来源：评论

学校读者我要写书评

暂无评论

Recent developments in Magneto-optic Garnet-type Thin-film Materials Synthesis

引用

Procedia engineering 2014年 76卷 61-73页

作者： Mohammad Nur-E-Alam Mikhail Vasiliev Viacheslav Kotov Kamal Alameh Electron Science Research Institute Edith Cowan University 270 Joondalup Drive Joondalup WA 6027 Australia Institute of Radio Engineering and Electronics RAS 11 Mohovaya St Moscow 125009 Russia

Magneto-optic (MO) garnets are used in a range of applications in nanophotonics, integrated optics, communications and imaging. Bi-substituted iron garnets of different compositions are the most useful class of materials in applied magneto- optics due to their excellent MO properties (large Faraday effect) and record-high MO figure of merit among all semi- transparent dielectrics. It is highly desirable to synthesise garnets which possess simultaneously a high MO figure of merit and large uniaxial magnetic anisotropy. However, the simultaneous optimization of several material properties and parameters can be difficult in single-layer garnet thin films, and it is also challenging to prepare films with high bismuth content using physical vapor deposition technologies. To meet the current challenge of developing next-generation functional MO materials, we design, develop and demonstrate the functionality of new magnetostatically-altered all-garnet multilayer heterostructures using two different garnet materials of dissimilar anisotropy types (out-of-plane and almost-in- plane). The multilayer structures possess simultaneously a high MO figure of merit and large uniaxial magnetic anisotropy together with low coercivity, if each of the layers is optimized in composition and annealed correctly. We prepare thin-film heterostructures by sandwiching a MO garnet layer with almost in-plane magnetization in-between two MO garnet layers with out-of-plane magnetization using RF sputtering. We apply customised high-temperature oven annealing processes (optimized in temperature and process durations after running many trials) for the as-deposited (amorphous) garnet multilayers to obtain the crystalline garnet phase in every layer. These structures then possess simultaneously a high optical/MO quality and low coercivity, which is very attractive for the development of magnetic photonic crystals, sensing devices and ultra-fast switches. Based on Bi-substituted ferrite garnets grown o

关键词： MO garnets nanocomposites co-sputtering multilayer heterostructures nanophotonics integrated optics magneto-photonic crystals magneto-plasmonic crystals.

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：