中国太阳能发电——政策是催化剂,降低发电成本是关键

一波三折的中国太阳能电池产业 2009年对于我国太阳能电池产业是一个不平凡的一年.2008年下半年开始的经济危机给欣欣向荣的太阳能电池行业泼了一盆冷水,国际多晶硅价格从每公斤500美元跌至100美元,欧洲太阳能市场停滞甚至萎缩.资料显示,2008年第四财季,无锡尚德电力控股公司亏损6590万美元,林洋新能源亏损6100万美元,江西赛维LDK亏损达1.33亿美元,一时间国内过半中小企业面临停产.光伏泡沫被金融危机戳破,我国的太阳能行业迎来了第一个冬天.     

薄膜晶体硅太阳能电池的潜力

如果效率和成本目标能够实现，薄膜晶体硅太阳能电池有潜力替代目前在光伏市场上占主导地位的多晶硅太阳能电池。     

太阳能用硅片技术及其进展

多晶硅片或单晶硅片是光伏产业链中太阳能电池片生产的基板材料。近年来,光伏产业的迅猛发展极大地促进了硅片制造技术和装备的飞速发展。文中介绍了当前晶体硅太阳能电池用硅片制备的主要工艺,并对其中的关键技术及发展状况进行了论述。     

合肥工业大学教授童国庆 开启半导体太阳能电池新时代

<正>太阳能取之不竭,用之不尽,清洁、高效、无污染。对太阳能的光电利用是近些年来发展最快、最具活力的研究领域,其中太阳能电池制备是研究的重中之重,备受关注。薄膜太阳能电池被认为是最具前途的太阳能电池技术。据统计,它的硅用量仅为硅片太阳能电池的1%左右,使得每瓦太阳能电池成本从2.5美元降至1.2美元。钙钛矿作为一种人工合成材料,在2009年被首次尝试应用于光伏发电领域后,因为性能优异、成本低廉、商业价值巨大,从此大放异彩。钙钛矿属于第三代太阳能电池,也称作新概念太阳能电池。     

多晶硅市场 冰火二重天

太阳能光伏产业受需求的扩张,引起供应严重短缺,自2004年以来,多晶硅价格一路飙升,2008年最高达450美元/公斤,投资光伏行业成为热门产业,但受金融危机的影响,半导体和光伏需求急剧下降,自2008年四季度以来,其价格如过山车一样,一路下跌,目前价格约为60美元左右。但受前两年多晶硅原料短缺影响,国内纷纷上马多晶硅生产项目,国     

国产太阳能电池设备今年销售额将超过5亿元

太阳能作为一种用之不竭又到处可取的无污染的清洁能源成为了人类首选的可再生能源。有专家分析．如果把地球表面0．1％的太阳能转变为电能．转变率为5％，每年的发电量相当于目前世界能耗的40倍左右。自20世纪80年代以来，光伏产业是世界上增长最快的高新技术产业之一。近年来．欧盟、美国、日本、澳大利亚等国都先后出台了利用太阳能发电的扶助政策，有力地推动了光伏产业的发展。与此同时，我国的太阳能电池设备也得到了快速的发展。自2003年以来．我国太阳能电池设备的销售额每年都以翻一番的速度增长，年均增长率达到97％。今年1—6月我国10家太阳能电池设备主要生产厂销售额已达到2．64亿元，相当于去年全年销售额的80％。其中，太阳能硅材料生长和加工设备上半年销售额1．43亿元，太阳能电池片制造设备销售额1．21亿元。预计今年我国太阳能电池设备销售额将超过5亿元。光伏产业的发展给我国电子专用设备行业带来了新的市场和发展机遇。     

光伏产业调整LED将席卷笔记本PC

全球对于太阳能的旺盛需求已导致用于生产太阳能电池的多晶硅出现严重短缺,促使光伏（PV）太阳能电池供应商调整业务结构和策略,以及寻找可替代的原材料。     

多晶硅:产量仍存缺口 质量亟待提高

<正>光伏产业对多晶硅的需求量,传统上以每瓦电池消耗10g多晶硅来进行计算,即每兆瓦电池需要10t多晶硅。但近年来,随着工艺技术的进步,晶体硅太阳能电池的多晶硅消耗量已降低到7~8g/W,甚至国内     

5亿美元,江苏大全集团大举切入多晶硅

据中国半导体设备及材料网网站报道:无锡尚德太阳能电力有限公司在纽交所上市后的财富效应带动了国内光伏产业链的投资热。江苏大全集团日前大举切入太阳能光伏上游——多晶硅。据悉,其与重庆万州区合作,总投资5亿美元、年产6000吨太阳能级和电子级多晶硅工厂项目上月底正式开工,这是目前国内开工建设的最大多晶硅原料生产项目。5亿美元,江苏大全集团大举切入多晶硅     

常州天合光能与韩国DCC签署长期多晶硅原料供应协议

据硅业在线网站报道,太阳能光伏产品生产商天合光能近日宣布与韩国DCC(东洋制铁化学)公司签署长期的多晶硅原料供应协议。DCC公司将为天合光能提供价值1.2亿美元左右的多晶硅原料,并将于2009年开始供货。天合光能的董事长兼执行总裁高纪凡接受采访时说:“我们很高兴能跟DCC公司     

Broadband scattering of the solar spectrum by spherical metal nanoparticles

Metal nanoparticles offer the possibility of improved light trapping in solar cells, but careful design is required to maximise scattering and minimise parasitic absorption across the wavelength range of interest. We present an analysis of the broadband scattering and absorption characteristics of spherical metal nanoparticles, optimized for either crystalline silicon (c‐Si) or amorphous silicon (a‐Si:H) solar cells. A random two‐dimensional array of optimally sized Ag spheres can scatter over 97% of the AM1.5 spectrum from 400 to 1100 nm. Larger particles are required for c‐Si devices than a‐Si:H due to the increased spectral range, with optimum particle sizes ranging from 60 nm for a‐Si:H to 116 nm for c‐Si. Positioning the particles at the rear of the solar cell decreases absorption losses because these principally occur at short wavelengths. Increasing the refractive index of the surrounding medium beyond the optimum value, which is 1.0 for a‐Si:H and 1.6 for c‐Si, shifts absorption to longer wavelengths and decreases scattering at short wavelengths. Ag nanoparticles scatter more of the solar spectrum than Au, Cu or Al nanoparticles. Of these other metals, Al can only be considered for a‐Si:H applications due to high absorption in the near‐infrared, whereas Au and Cu can only be considered for the rear of c‐Si devices due to high absorption in the ultraviolet (UV) and visible. In general, we demonstrate the importance of considering the broadband optical properties of metal nanoparticles for photovoltaic applications. Copyright © 2012 John Wiley & Sons, Ltd.     

8% Efficient thin‐film polycrystalline‐silicon solar cells based on aluminum‐ induced crystallization and thermal CVD

A considerable cost reduction could be achieved in photovoltaics if efficient solar cells could be made from polycrystalline‐silicon (pc‐Si) thin films on inexpensive substrates. We recently showed promising solar cell results using pc‐Si layers obtained by aluminum‐induced crystallization (AIC) of amorphous silicon in combination with thermal chemical vapor deposition (CVD). To obtain highly efficient pc‐Si solar cells, however, the material quality has to be optimized and cell processes different from those applied for standard bulk‐Si solar cells have to be developed. In this work, we present the different process steps that we recently developed to enhance the efficiency of pc‐Si solar cells on alumina substrates made by AIC in combination with thermal CVD. Our present pc‐Si solar cell process yields cells in substrate configuration with efficiencies so far of up to 8·0%. Spin‐on oxides are used to smoothen the alumina substrate surface to enhance the electronic quality of the absorber layers. The cells have heterojunction emitters consisting of thin a‐Si layers that yield much higher V_oc values than classical diffused emitters. Base and emitter contacts are on top of the cell in interdigitated finger patterns, leading to fill factors above 70%. The front surface of the cells is plasma textured to increase the current density. Our present pc‐Si solar cell efficiency of 8% together with the fast progression that we have made over the last few years indicate the large potential of pc‐Si solar cells based on the AIC seed layer approach. Copyright © 2007 John Wiley & Sons, Ltd.     

Moving software to a global platform

The 1990s has already seen enormous change to the computer industry in Brazil. But the greatest change of all is expected in the area of software. By the end of 2000, Brazil is out to capture 1 percent of a US $ 200 billion international software market, according to the federal Govemment's National Program of Software for Export, or Softex 2000. For Brazil, this could mean $2 billion in revenues from sales of application programs, programming tools, and multimedia entertainment and educational systems on CD-ROMs. So far, the local industry has done well. Exports in 1995 reached $100 million, about half going to the United States, again according to Softex. This occurred even though most of the Softex-supported companies still have to make their mark overseas. In 1994, Brazilian companies sold a total of $1.1 billion worth of software, which puts the industry on a par with that of India's far better known software industry, though exports account for about half of India's revenues. Brazil's software industry grew by about 25 percent over the year before. Revenues from information technology hardware, software, and services in 1994 were around 2 percent of Brazil's gross domestic product of about $552 billion     

Efficient silicon heterojunction solar cells based on p‐ and n‐type substrates processed at temperatures < 220°C

We present the optimization and characterization of heterojunction solar cells consisting of an amorphous silicon emitter, a single crystalline absorber and an amorphous silicon rear side which causes the formation of a back surface field (a‐Si:H/c‐Si/a‐Si:H). The solar cells were processed at temperatures <220°C. An optimum of the gas phase doping concentration of the a‐Si:H layers was found. For high gas phase doping concentrations, recombination via defects located at or nearby the interface leads to a decrease in solar cell efficiency. We achieved efficiencies >17% on p‐type c‐Si absorbers and >17·5% on n‐type absorbers. In contrast to the approach of Sanyo, no additional intrinsic a‐Si:H layers between the substrate and the doped a‐Si:H layers were inserted. Copyright © 2006 John Wiley & Sons, Ltd.     

Low-cost industrial technologies of crystalline silicon solar cells

Approximately 2 billion people, mainly in Third World countries, are not connected to an electric grid. The standard, centralized grid development is too expensive and time consuming to solve the energy demand problem. Therefore, there is a need for decentralized renewable energy sources. The main attractiveness of solar cells is that they generate electricity directly from sunlight and can be mounted in modular, stand-alone photovoltaic (PV) systems. Particular attention is paid in this paper to crystalline silicon solar cells, since bulk silicon solar-cell (mono and multi) modules comprise approximately 85% of all worldwide PV module shipments. Energy conversion efficiency as high as 24% has been achieved on laboratory, small-area monocrystalline silicon cells, whereas the typical efficiency of industrial crystalline silicon solar cells is in the range of 13-16%. The market price of PV modules remains for the last few years in the range of $3.5-4.5/watt peak (Wp). For the photovoltaic industry, the biggest concern is to improve the efficiency and decrease the price of the commercial PV modules. Efficiency-enhancement techniques of commercial cells are described in detail. Adaptation of many high-efficiency features to industrially fabricated solar cells. The latest study shows that increasing the PV market size toward 500 MWp/y and accounting for realistic industrial improvements can lead to a drastic PV module price reduction down to $1/Wp     

May The Force of Light Be With You

Countless research institutions contributed to the digital, wireless, and mobile technologies that underpin our modern world. But none contributed more than Bell Telephone Laboratories, which logged an astonishing share of the key advances of the 20th century, including the transistor, the cellphone, the digital signal processor, the laser, the Unix operating system, and motionpicture sound. We no longer have Bell Labs to fund research with long-term payback. That has prompted many to wonder: Who will pay for such research now, and where will it be done? We say: Governments and corporations must share the burden, and they must do it in structured collaborations among universities, companies, and government agencies in which intellectual property is freely available to all participants. We also say, the sooner we can get started, the better. The recession has left R&D spending in free fall. This year, the global semiconductor industry is expected to spend just US $200 billion on research-$50 billion less than in 2008. And times are really tough in the semiconductor equipment industry, whose R&D operations will shrivel like a salted leech from $34 billion in 2007 down to a pitiful $10 billion in 2009.     

无机半导体太阳能电池的网印技术要领

太阳能电池是一种无污染、供量大的产品,它通过光电变换从太阳能获得电能。太阳能电池是一种有效地吸收太阳能辐射并使之转化为电能的半导体电子器件,广泛应用于各种照明及发电系统中。文章介绍无机半导体太阳能电池的网印技术。     

Role of radiation-hard solar cells in minimizing the costs of global satellite communication systems

An analysis embodied in a personal computer program is presented, which quantitatively demonstrates how the availability of radiation hard-solar cells can help to minimize the cost of a global satellite communication system. An important distinction between the currently proposed systems, such as Iridium, Odyssey and Ellipsat, is the number of satellites employed and their operating altitudes. Analysis of the major costs associated with implementing these systems shows that operation at orbital altitudes within the Earth's radiation belts (10³–10⁴ km) can reduce the total cost of a system by several hundred per cent,^1,2 so long as radiation-hard components, including solar cells, can be used. A detailed evaluation of the predicted performance of photovoltaic arrays using several different planar solar cell technologies is given, including commercially available Si and GaAs/Ge, and InP/Si which is currently under development. Several examples of applying the program are given, which show that the end-of-life (EOL) power density of different technologies can vary by a factor of ten for certain missions. Therefore, although a relatively radiation-soft technology can usually provide the required EOL power by simply increasing the size of the array, the impact upon the total system budget could be unacceptable, due to increased launch and hardware costs. In aggregate, these factors can account for more than a 10% increase in the total system cost. Because the estimated total costs of proposed global-coverage systems range from $1 billion to $9 billion, the availability of radiaton-hard solar cells could make a decisive difference in the selection of a particular constellation architecture.     

Zone-melting recrystallization of silicon thin films for solar cell application

Zone-melting recrystallization (ZMR) has been applied successfully to fabricate a thin-film silicon solar cell with high conversion efficiency that also has the potential to lower the material cost. It is found that seeding from an Si substrate during ZMR is not necessary for high-quality thin-film Si with a low defect density and the dominant (100) crystallographic orientation. This feature is very important because one can separate the thin-film Si from the substrate in order to obtain a flexible solar cell and the substrate can be recycled. Lowering the scanning speed of the upper movable carbon strip heater has proved to be most effective for high-quality crystal. In order to realize thin-film Si solar cells, a 60-μm thick Si active layer is deposited by chemical vapour deposition on recrystallized Si film. Pyramidal shape formation at the surface for light confinement by using (100) orientation and low-energy H⁺ ion irradiation for the passivation of crystal defects has been applied to the fabrication of thin-film Si solar cells and we achieved high conversion efficiencies of more than 14% for a 10 × 10 cm² cell and 16% for a 2 × 2 cm² cell.     

About the origin of low wafer performance and crystal defect generation on seed‐cast growth of industrial mono‐like silicon ingots

The era of the seed‐cast grown monocrystalline‐based silicon ingots is coming. Mono‐like, pseudomono or quasimono wafers are product labels that can be nowadays found in the market, as a critical innovation for the photovoltaic industry. They integrate some of the most favorable features of the conventional silicon substrates for solar cells, so far, such as the high solar cell efficiency offered by the monocrystalline Czochralski‐Si (Cz‐Si) wafers and the lower cost, high productivity and full square‐shape that characterize the well‐known multicrystalline casting growth method. Nevertheless, this innovative crystal growth approach still faces a number of mass scale problems that need to be resolved, in order to gain a deep, 100% reliable and worldwide market: (i) extended defects formation during the growth process; (ii) optimization of the seed recycling; and (iii) parts of the ingots giving low solar cells performance, which directly affect the production costs and yield of this approach. Therefore, this paper presents a series of casting crystal growth experiments and characterization studies from ingots, wafers and cells manufactured in an industrial approach, showing the main sources of crystal defect formation, impurity enrichment and potential consequences at solar cell level. The previously mentioned technological drawbacks are directly addressed, proposing industrial actions to pave the way of this new wafer technology to high efficiency solar cells. Copyright © 2012 John Wiley & Sons, Ltd.