多晶硅常识一二三

·硅在自然界中分布极广,地壳中约含27.6%,仅次于氧。·冶金级硅是二氧化硅与焦炭在电弧炉中反应形成,其纯度在97%～99%,用于冶金或化学工业。·太阳能级多晶硅用冶金级硅提纯,其纯度达到99.9999%以上。·太阳能级多晶硅生产主要使用改良西门子法、硅烷法、冶金法等生产。     

硅管西门子法多晶硅及物理冶金法多晶硅制备

论述了:1)使用本征导电性硅环作为籽晶,采用直拉硅单晶炉及切克劳斯基法拉制等径的具有p型、n型或本征导电性的硅管;2)用p型或n型硅管作为化学西门子法还原炉中的热载体,当载体加热温度在1050~1100℃时,还原炉内高纯氢及三氯氢硅反应生成的硅沉积在热载体上,制备纯度99.99999%以上的本征或导电性的硅管多晶硅;3)用本征导电性的硅管作为容器,装入纯度大于99.99%的物理冶金法生产的原料硅,采用区熔单晶硅炉,用悬浮区域炼熔法对硅管多次定向凝固,利用分凝效应制备纯度大于99.9999%的硅管太阳能级多晶硅棒。     

RTCVD沉积轻掺和不掺硼多晶硅薄膜结构和电学性能的研究

利用快速加热化学气相沉积(RTCVD)系统在高纯石英衬底上分别制备了轻掺和不掺硼的多晶硅薄膜,并利用XRD、SEM高阻Hall测量和光电导谱测量技术研究了它们的结构和电学性能.结果表明,1150℃在石英衬底上生长的本征多晶硅薄膜具有[111]择优生长取向,而轻掺硼的多晶硅薄膜则同时具有[311]和[200]两个晶向上的择优取向.通过轻微掺入硼,多晶硅薄膜晶粒尺寸分布的均匀性得到了很大改善.高阻Hall测量表明轻掺硼的多晶硅薄膜具有更高的Hall迁移率因而具有更好的电学性能.光电导谱则量结果表明所制备的多晶硅薄膜的光学带隙与晶体硅的非常接近,在1.1eV.     

2010年冶金法太阳能级多晶硅产业技术进展

随着光伏发电成本的降低,光伏电池的产量和应用量越来越大,对太阳能级多晶硅的需求也越来越大。目前的太阳能多晶硅原料绝大多数都是采用金属硅为原料,用盐酸反应成三氯氢硅后气化精馏提纯,得到纯三氯氢硅后,再用氢气还原得到纯硅。这就是西门子法多晶硅,通常,其纯度可以达到9N以上。西门子法多晶硅原来主要用于制作半导体器件,光伏应用发展起来以后,也开始成为光伏电池所用的太阳能级多晶硅的主要生产工艺。但太阳能级多晶硅的最佳纯度应当是6N(99.9999%),因为纯度在7N以上的多晶硅电阻率过高,通常在     

多晶硅工艺线路比较

1 改良西门子法 改良西门子法是先用氯和氢合成氯化氢(或外购氯化氢),氯化氢和工业硅粉在一定的温度下合成三氯氢硅,再对三氯氢硅进行分离精馏提纯,提纯后的三氯氢硅在氢还原炉内进行CVD反应生成高纯多晶硅.国内外现有的多晶硅厂绝大部分采用此法生产电子级与太阳能级多晶硅.     

三层液电解精炼提纯冶金级硅研究

在氟化物熔盐电解质体系下,把Cu与冶金级多晶硅熔配成合金作为阳极硅源,利用杂质与硅析出电位的差别,通过控制电解工艺条件和参数,对冶金硅进行了电解精炼提纯研究.结果表明:电解过程平稳,且电流效率保持95%以上;阴极电沉积硅呈颗粒状,尺寸约为100μm;随着电解时间的延长,分散的硅的颗粒有聚集成大尺寸硅球的趋势.ICP-AES分析表明,最后得到的产物硅与冶金级硅相比,硼含量由12.7mg/kg降低到2.4mg/kg,磷含量由98.6mg/kg减少到4.3mg/kg.     

冶金级硅及太阳能级硅的生产

提出了冶金级硅及太阳能级硅的先进生产方法,讨论了在熔炼硅时产生的化学反应及如何利用感应炉去除冶金级硅中杂质的有效方法,以及介绍了单晶硅锭和多晶硅锭的生产方法。     

光伏产业新动力：高纯冶金级硅太阳电池产品投入市场——CSI阿特斯宣布UMG组件e-Modules正式下线

6月中旬,在德国慕尼黑的Intersolar展会上,CSI阿特斯隆重推出用冶金硅提炼成太阳能级硅片生产的新组件产品,并命名为e-Module,使之成为世界上成功实现高纯冶金硅(UMG-Si)提炼成太阳能级硅片商业化生产的公司之一.     

低耗无污新工艺“蒸”出低价太阳能级多晶硅

2010年6月18日,由南阳迅天宇硅品有限公司、中科院上海技术物理研究所联合研发的物理法太阳能级多晶硅全流程工艺,通过了中科院上海分院专家的成果鉴定。这项技术填补了国际上没有专门面向光伏产业的多晶硅工业技术的空白,标志着我国已经超越发达国家,在节能环保的低成本太阳能级多晶硅制造新技术领域取得了重大突破。     

谈谈我国多晶硅产业面临的主要问题

当前我国多晶硅项目投资火热,从技术上看,国内多晶硅企业及拟上马的多晶硅项目大多采用俄罗斯的生产技术,也有部分企业在消化、吸收俄罗斯技术的基础上,进行了进一步的研发(洛阳中硅、峨嵋半导体等),还有企业正全面研究物理法(河南迅天宇).在此分析一下我国多晶硅产业面临的主要问题.     

Refining of metallurgical-grade silicon by inductive plasma

A new process combining inductive plasma torch and electromagnetic stirring of molten silicon in a cold crucible has been developed to refine upgraded metallurgical silicon. The addition of reactive gases to the plasma leads to volatilisation of impurities at the liquid silicon surface. The concentration of boron impurities decreased from 15 ppmw in the raw material to less than 2 ppmw after the plasma treatment. The most volatile form of boron was BOH, which was obtained by simultaneous treatment with oxygen and hydrogen. The limitation in boron volatilisation is due to the formation, at high oxygen flow rate, of a silica layer at the surface of the molten silicon, which results in a dramatic drop of the volatilisation rate. In contrast to boron, the concentration of phosphorus was reduced by only a factor of two, although the remainder seems to be electrically neutral. Thermodynamic studies suggest that phosphorus could be trapped as phosphate in combination with metallic impurities. Cells made of material produced using this technique exhibited a conversion efficiency of 12.4%.     

24对棒多晶硅还原炉的辐射传热数值模拟

在还原炉中制备多晶硅需要密闭且高温的环境,用传统检测方法获得炉内温度场分布比较困难。本文基于FLUENT仿真计算平台,对硅棒生长至50、100、150 mm时的24对棒多晶硅还原炉的辐射传热进行三维数值模拟,得出还原炉内不同硅棒直径时的温度场分布。通过比较模拟的出口尾气温度与多晶硅实际生产中出口尾气的温度,验证模拟结果的可靠性。探讨温度对多晶硅生长的影响,为操作人员在多晶硅生产中控制炉内温度提供理论指导。     

Inkjet printed nickel silicide applied as front contact seed-layer for electrolessly copper plated silicon solar cells

Abstract

The use of high purity nickel silicon nano-inks represents a new approach to the design of conductive electrode structures, with potential to reduce electrode cost by up to 75% by reducing silver usage. In addition to reducing manufacturing costs, utilising nickel silicon inks would greatly improve product throughput. However, careful design and incorporation of a nickel barrier layer are required to prevent copper poisoning of the solar cell. Once proven, this technology could be readily incorporated into existing production facilities (the majority of solar cell process tooling remaining as standard), thereby providing a ready route to a mass market. The status of the Innovate UK funded Propress R&D project is reported and the specialised equipment, nano-inks and processes developed are described. An evaluation of the cell efficiencies obtained using this alternative cell processing technology is presented, alongside stability and performance data.     

New technologies for solar energy silicon—Cost analysis of dichlorosilane process

New technologies for producing polysilicon are being developed to provide lower cost material for solar cells which convert sunlight into electricity. This article presents results for a process to produce dichlorosilane (DCS) as a silicon source material for solar energy silicon. Major benefits of dichlorosilane include faster chemical vapor deposition of silicon and higher chemical equilibrium yield for silicon production. Hemlock Semiconductor Corporation has recently demonstrated that under comparable conditions and for rods up tp 42 mm dia., deposition rates and conversions for dichlorosilane are approximately twice those for trichlorosilane. Cost, sensitivity and profitability analysis results are presented based on a preliminary process design of a plant to produce dichlorosilane by the DCS process. Profitability analysis indicates a sales price of $1.29–$1.47/kg of dichlorosilane (1980 dollars) at a 0–15 per cent discounted cash flow rate of return after taxes. These results indicate good potential for dichlorosilane as a silicon source material to provide lower cost material for solar cells.     

Toward GW/year of CIGS production within the next decade

A detailed study carried out in 1996–1997 showed that manufacturing cost of crystalline silicon PV modules could be lowered to 1 ECU/Wp when the c-Si annual module production level reaches 500 MWp while an annual production of only 60 MWp would lower production cost of thin-film PV modules to 0.6 ECU/Wp. During 1976–2003, the PV module price has followed the 80% learning curve with cumulative production volume. However, the price reduction has slowed since because of the polysilicon supply problem. Because of their high potential for improvement, thin-film PV and especially copper (Cu)–indium (In)–gallium (Ga)–selenide (Se)-sulfide (CIGS) technology have the potential for growing at the fastest rate and consequently not only to complement the lagging c-Si PV production but also to assist in following the 80% learning curve. This paper reviews the CIGS PV manufacturing processes in comparison to those of other PV technologies and predicts that annual production volume of CIGS thin-film PV modules will exceed 1 GW/year within the next 10 years.     

多晶硅片单面制绒工艺的研究

介绍了一种新的多晶硅片单面制绒工艺,通过对太阳能多晶硅链式制绒设备进行改造,使制绒槽内的硅片由浸没式腐蚀制绒改为漂浮式腐蚀制绒,同时利用喷淋方式去除硅片背面的损伤层,可有效避免硅片背面的过度腐蚀.通过选定相同条件下的多晶硅原料片,并进行严格均分,分别采用单面制绒工艺与产线常规双面制绒工艺进行制绒,其他工序采用相同设备及...     

New technologies for solar energy silicon: Cost analysis of BCL process

New technologies for producing polysilicon are being developed to provide lower cost material for solar cells which convert sunlight into electricity. This article presents results for the BCL Process (Battelle Columbus Laboratories), which produces the solar-cell silicon by reduction of silicon tetrachloride with zinc vapor. The UCC Silane Process (Union Carbide Corporation) was reported in a previous article.Cost, sensitivity and profitability analysis results are presented based on a preliminary process design of a plant to produce 1000 metric tons/year of silicon by the BCL Process. Profitability analysis indicates a sales price of 12.1–19.4$/kg of silicon (1980 dollars) at a 0–25 per cent DCF rate of return on investment after taxes. These results indicate good potential for meeting the goal of providing lower cost material for silicon solar cells.     

Chemical treatment of crystalline silicon solar cells as a method of recovering pure silicon from photovoltaic modules

Photovoltaic technology is used worldwide to provide reliable and cost-effective electricity for industrial, commercial, residential and community applications. The average lifetime of PV modules can be expected to be more than 25 years. The disposal of PV systems will become a problem in view of the continually increasing production of PV modules. These can be recycled for about the same cost as their disposal.Photovoltaic modules in crystalline silicon solar cells are made from the following elements, in order of mass: glass, aluminium frame, EVA copolymer transparent hermetising layer, photovoltaic cells, installation box, Tedlar^® protective foil and assembly bolts. From an economic point of view, taking into account the price and supply level, pure silicon, which can be recycled from PV cells, is the most valuable construction material used.Recovering pure silicon from damaged or end-of-life PV modules can lead to economic and environmental benefits. Because of the high quality requirement for the recovered silicon, chemical processing is the most important stage of the recycling process. The chemical treatment conditions need to be precisely adjusted in order to achieve the required purity level of the recovered silicon. For PV systems based on crystalline silicon, a series of etching processes was carried out as follows: etching of electric connectors, anti-reflective coating and n-p junction. The chemistry of etching solutions was individually adjusted for the different silicon cell types. Efforts were made to formulate a universal composition for the etching solution. The principal task at this point was to optimise the etching temperature, time and alkali concentration in such a way that only as much silicon was removed as necessary.     

多晶硅还原炉高频交流电加热机制研究

以多晶硅还原炉硅棒焦耳电加热过程为研究对象,考虑辐射、对流以及化学反应热3种热量传递形式,耦合频率控制的电磁场模型,建立硅棒焦耳电加热模型。基于该模型,分析不同频率下24对棒还原炉内、中、外环上硅棒内部温度及电流密度分布。研究表明,交流电频率越高,硅棒内部温度分布越均匀。当相对频率RF>10时,硅棒中心附近存在恒温区,且RF增大,恒温区范围增大。利用高频电流产生的趋肤效应可有效改善硅棒内部温度梯度,为实现增大硅棒最终沉积半径提供潜在的可能。模型预测得到低频(50 Hz)和高频(10和50 kHz)条件下电压-电流操作曲线,提出低频和高频交流电联合焦耳电加热方式。     

基于多晶硅金刚线切割工艺的光伏生命周期分析

金刚线切割工艺已经成为当今光伏产业硅片生产的主流技术.该文采用生命周期分析方法,以1 kW多晶硅太阳电池光伏发电系统为模型,研究使用金刚线切割工艺替代原来的砂浆切割技术后,这一技术更新所带来的光伏产品的能耗和碳排放量的降低效应.计算表明:应用金刚线切割工艺的光伏系统生命周期碳排放为1358.53 kg/kW,金刚线切割...