电化学沉积法制备Cu_2ZnSnS_4薄膜电池

采用简单的两电极电化学沉积金属薄膜技术,在镀钼的钠钙玻璃衬底上共沉积Cu-Sn层后,再沉积Zn金属层,制备出Cu-Sn-Zn金属预制层。在不同的温度下进行低温退火后,以硫粉作为硫源高温硫化金属预制层,制备出晶体质量较好的Cu2ZnSnS4(CZTS)薄膜。通过X射线衍射仪(XRD)、扫描电镜(SEM)及能谱仪(EDS)对薄膜的晶体结构、表面形貌和薄膜组分进行分析表征,发现共沉积Cu-Sn层,再沉积Zn金属层得到的CZT预制层表面平整但晶粒尺寸较小,经过退火处理后晶粒尺寸得到改善,且硫化后所得到的CZTS薄膜不易从Mo衬底上脱落,粘附性较强。用其制备的CZTS薄膜太阳电池的开路电压Voc=569mV,短路电流密度Jsc=8.58mA/cm2,光电转换效率为1.40%。     

共蒸发法制备Cu_2ZnSnS_4薄膜的研究

利用真空蒸镀技术共蒸发Cu,Zn,Sn金属丝在玻璃衬底上制备前驱体Cu-Zn-Sn(CZT),并采用高温硫化金属前驱体的方法制备Cu2Zn Sn S4(CZTS)薄膜。本文采用X射线衍射和扫描电子显微镜对薄膜进行表征,探究前驱体的蒸镀条件以及硫化温度对薄膜生长情况的影响,结果表明:溅射Mo作为缓冲层有利于Zn原子的沉积;硫化温度为500℃时,薄膜的结晶度较好,能够生成单一的CZTS薄膜;气压越低越有利于形成优质薄膜;衬底温度升高为220℃时,薄膜的结晶度有所提高,有利于抑制杂质的生成;等离子体的辅助可以提高薄膜的结晶质量。     

用Zn掺杂和热处理改善SnS薄膜的电学特性

用质量比为1%∶0.2%(质量分数)的Sn、S混合粉末在玻璃衬底上热蒸发沉积SnS薄膜,氮气保护下对薄膜进行350℃、40min热处理后,得到简单正交晶系SnS多晶薄膜,薄膜的电阻率为103Ω.cm,选择2%和4%(质量分数)的Zn掺杂来改善SnS薄膜的导电性。研究表明,SnS∶Zn薄膜最有效的热处理条件为300℃、40min,掺Zn后薄膜的物相结构转为简单正交和面心正交晶系混合相,SnS∶Zn薄膜(2%和4%(质量分数))的电阻率在1.8528×10-3～4.944×10-4Ω.cm之间,导电类型为N型。薄膜中Sn和S分别呈+2和-2价,Zn显示+2价,以间隙和替位两种状态存在于SnS中,对薄膜导电性起改善作用的是间隙态的Zn离子。     

H2S气氛下硫化温度对Cu2ZnSnS4薄膜性能影响的研究

用磁控溅射法在玻璃衬底上沉积Zn/Sn/Cu预置层,然后再在H2S气氛下将其硫化制成Cu2ZnSnS4(CZTS)薄膜。研究了不同硫化温度(460,500,540和580℃)对CZTS薄膜性能的影响。采用X射线衍射、Raman、扫描电镜、能量色散谱和紫外-可见-近红外分光光度计表征薄膜的物相、表面形貌和光学性能。结果表明,在不同硫化温度下都成功制备了CZTS薄膜。当硫化温度为540℃时,制备的薄膜晶粒达到2μm,结晶性最好,表面致密光滑,而且它的吸收系数大于7×104cm-1,禁带宽度为1.49 e V。硫化温度较低(460℃)时,含有Cu2-xS杂质相,表面存在孔洞。而硫化温度较高(580℃)时,晶界处会产生微裂纹。     

Zn掺杂SnS薄膜的表征及光学特性

真空共蒸发制备掺Zn(2%,4%(质量比))的SnS薄膜。研究热处理对Zn掺杂SnS薄膜的结构、表面形貌、化学组分及光学特性的影响。实验给出2%掺Zn薄膜经300℃,40 min热处理后,得到正交晶系的SnS多晶薄膜。掺Zn可一定程度抑制薄膜中S的损失,使薄膜体内Sn∶S元素化学计量得到改善,从未掺Zn的Sn∶S比为1.90∶1降到1.38∶1(2%)及1.36∶1(4%)。掺Zn后SnS薄膜的吸收边都发生红移,光吸收系数高达105cm-1。未掺Zn薄膜的直接光学带隙1.95 eV,掺Zn是1.375 eV(2%)和1.379 eV(4%)。Sn和S在薄膜中分别呈+2和-2价态,Zn以间隙和替位两种状态存在。     

硫化温度对铜锌锡硫薄膜特性的影响

采用预制膜硫化法制备铜锌锡硫(CZTS)薄膜,分别在350,400,450,500,550℃进行硫化,研究了硫化温度对薄膜特性的影响。结果表明:硫化温度低于400℃时硫化反应基本上不发生,主要发生Cu6Sn5和Cu5Zn8两相中元素相互扩散的合金化过程,只有少量硫化物Sn3S4和ZnS生成;硫化温度为450℃时,合金相消失,硫化后的薄膜同时含有CZTS和SnS;硫化温度为500℃时薄膜的主要组成相为CZTS,其晶粒尺寸达2μm,但表面粗糙;硫化温度为550℃薄膜中CZTS晶粒尺寸约为2μm,表面平整。     

溶胶-凝胶法制备CZTS太阳能电池吸收层薄膜

Cu2ZnSnS4(CZTS)具有与CIGS相似的结构,其直接带隙宽度为1.45~1.6eV,吸收系数则高于104cm-1,构成元素丰富且无毒,因此其作为一种P型半导体材料,被认为是最有希望替代CIGS的材料之一。以去离子水和无水乙醇作为溶剂,采用溶胶-凝胶法(Sol-gel)在玻璃基底上制得了CZTS薄膜,利用X射线衍射仪、拉曼光谱仪、扫描电镜和紫外可见光谱对样品进行了表征,并讨论了烘焙温度对薄膜结构和形貌的影响。结果表明当热处理温度达到200℃时得到了黑色的CZTS薄膜,其禁带宽度为1.45eV,经过EDS分析制得的薄膜的元素比Cu∶Zn∶Sn∶S接近2∶1∶1∶4,这与CZTS的理论值是一致的,但是薄膜中存在少量的氯元素,同时适当降低前期的烘焙温度可以提高薄膜的致密性。     

掺Zn改善SnS2光电薄膜的性能

热蒸发制备Zn掺杂SnS2薄膜,研究不同Zn含量及热处理条件对薄膜的物相结构、表面形貌和光电性能的影响。实验给出用Sn∶S=1∶1.08(wt)混合粉末沉积的薄膜,经380℃、15min热处理后得到简单正交晶系的SnS2薄膜;9(wt%)掺Zn后的薄膜热处理条件为370℃、20min。Sn、S和Zn分别以正4价、负2价和正2价存在于薄膜中。SnS2薄膜的直接光学带隙为2.12eV,掺Zn后为2.07eV;薄膜的电阻率从未掺Zn时的4.97×102Ω.cm降低到2.0Ω.cm,下降了两个数量级,所有SnS2薄膜导电类型均为N型。     

Cu2ZnSnS4薄膜光电性能及其太阳电池的制备和研究

采用硫化Zn/Sn/Cu金属多层膜的方法制备了太阳电池吸收层用的Cu2ZnSnS4(CZTS)薄膜。用X射线衍射仪、拉曼光谱仪、紫外-可见近红外分光光度计、扫描电镜、能谱仪及数字源表等对薄膜进行了一系列的表征。结果表明制备的CZTS薄膜没有杂相存在并具有标准拉曼峰。薄膜在可见光范围内的吸收系数>104cm-1,同时其光学带隙接近1.5eV。CZTS薄膜具有均匀致密的表面形貌,薄膜元素比例非常接近标准化学计量比。此外,CZTS薄膜呈现显著的光电流响应性能,其光电流的激发和衰减时间分别为0.0736和0.2646s。     

硫化时间对固态硫化铜锌锡硫薄膜性能的影响

采用固态硫化法硫化铜锡锌(CZT)预制膜制备铜锌锡硫(Cu_2ZnSnS_4,CZTS)薄膜,研究硫化时间对CZTS薄膜性能的影响。利用X射线衍射仪(XRD)和紫外拉曼光谱仪(Raman)分析薄膜的物相结构,通过X射线能谱仪(EDS)分析薄膜的化学组分,采用扫描电镜(SEM)观察薄膜的表面形貌,利用UV-Vis研究薄膜的光学特性。结果表明:随着硫化时间延长,Cu含量增加,Zn含量明显减少。硫化40min以上制备的薄膜出现导致禁带宽度减小的杂相SnS,Sn2S3和Cu_2SnS_3。当硫化时间为20min时,样品为单相的CZTS薄膜,薄膜表面均匀平整,化学组分贫Cu富Sn,吸收系数达104cm-1,禁带宽度Eg约为1.56eV。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...