检索结果-南通市图书馆

light concentration using hetero-junctions of anisotropic low permittivity metamaterials

light(Science & Applications) 2013年第1期2卷 18-26页

作者： Mohammad Memarian George V Eleftheriades The Edward S.Rogers Sr.Department of Electrical and Computer Engineering University of TorontoTorontoOnt.M5S 2E4Canada

Focusing incident power into an area of high concentration is of significant interest for various *** optics,this has been traditionally achieved with lenses where a higher curvature and lens permittivity typically result in shorter focal distances(low f/D).In this work,we present designs and techniques for collecting,refracting and guiding incident light into an area of high power concentration(a hot spot)at extremely short ***,a flat low-profile focusing mechanism is presented using a hetero-junction of anisotropic metamaterials(MTMs).The hetero-junction is formed from two cleaved finite slabs of low(near zero)permittivity anisotropic MTMs with rotated optical *** MTMs have near zero longitudinal permittivity while matched in the transverse *** MTMs are shown to provide a unique ability to bend the transverse magnetic or p-polarized light away from the normal and along the interface,contrary to conventional dielectrics,and with minimal reflections;hence allowing for a low profile *** in the optical regime are presented using periodic bilayers of metal and *** proposed hetero-junction focusing device concentrates the normally incident plane wave and/or beam into a corresponding focal region similar to a lens via multiple *** hetero-junction is capable of creating a hot spot very close to the device,much closer than dielectric lenses and it significantly outperforms the size requirements of thick high curvature lenses with low f/D *** proposed designs can find applications in various scenarios including solar and thermo photovoltaics,photodetectors,concentrated photovoltaics,non-imaging optics,micro-and nano-Fresnel lenses.

关键词： epsilon near zero focusing light concentration metamaterials non-imaging optics photovoltaics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Temperature Effect on light concentration Silicon Solar Cell’s Operating Point and Conversion Efficiency

引用

Smart Grid and Renewable Energy 2020年第5期11卷 61-72页

作者： Mahamadi Savadogo Boubacar Soro Ramatou Konate Idrissa Sourabié Martial Zoungrana Issa Zerbo Dieudonné Joseph Bathiebo Laboratory of Thermal and Renewable Energies Department of Physics Unit of Training and Research in Pure and Applied Sci-ences University Joseph KI-ZERBO Ouagadougou Burkina Faso

It is well known that temperature acts negatively on practically all the parameters of photovoltaic solar cells. Also, the solar cells which are subjected to particularly very high temperatures are the light concentration solar cells and are used in light concentration photovoltaic systems (CPV). In fact, the significant heating of these solar cells is due to the concentration of the solar flux which arrives on them. Light concentration solar cells appear as solar cells under strong influences of heating and temperature. It is therefore necessary to take into account temperature effect on light concentration solar cells performances in order to obtain realistic results. This one-dimensional study of a crystalline silicon solar cell under light concentration takes into account electrons concentration gradient electric field in the determination of the continuity equation of minority carriers in the base. To determine excess minority carrier’s density, the effects of temperature on the diffusion and mobility of electrons and holes, on the intrinsic concentration of electrons, on carrier’s generation rate as well as on width of band gap have also been taken into account. The results show that an increase of temperature improves diffusion parameters and leads to an increase of the short-circuit photocurrent density. However, an increase of temperature leads to a significant decrease in open-circuit photovoltage, maximum electric power and conversion efficiency. The results also show that the operating point and the maximum power point (MPP) moves to the open circuit when the cell temperature increases.

关键词： Temperature Electric Power Conversion Efficiency light concentration Maximum Power Point Junction Dynamic Velocity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Preparation of Plasmonic Au Superstructures for Significantly Visible-light-enhanced Catalytic Reactions

Preparation of Plasmonic Au Superstructures for Significantl...

引用

中国化学会第九届全国无机化学学术会议

作者： Ying Li Jie Li Jinhu Yang Department of Chemistry Tongji University Institute for Biomedical Engineering & Nano Science Tongji University

Noble metals are well-known for their surface plasmon resonance effect that enables strong light absorption typically in the visible regions for gold and silver [1, 2]. However, unlike semiconductors, noble metals are commonly considered incapable of catalyzing reactions via photo-generated electron-hole pairs due to their continuous energy band structures. So far, photonically-activated catalytic system based on pure noble metal nanostructures has seldom been reported [3]. Here, we report the development of three different novel plasmonic Au superstructures comprised of Au nanoparticles, multiple-twinned nanoparticles and nanoworms assembling on the surfaces of Si O2 nanospheres respectively via a well-designed synthetic strategy. It is found that these novel Au superstructures show enhanced broadband visible light absorption due to the plasmon resonance coupling within the superstructures, thus can effectively focus the energy of photon fluxes to generate much more excited hot electrons and holes for promoting catalytic reactions. Accordingly, these Au superstructures exhibit significantly visible-light-enhanced catalytic efficiency(up to 64% enhancement) for the commercial reaction of p-nitrophenol reduction(Figure 1). These novel superstructures will pave a new way to developing metallic catalytic devices and related energy applications.

关键词： Noble metal Au plasmonic superstructures light concentration Visible-light-enhanced catalytic reactions

来源： cnki会议 cnki会议评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

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：