Cu_2ZnSnS_4纳米晶及其薄膜的制备

以乙酰丙酮铜(Cu(AcAc)2)、乙酸锌(Zn(CH3COO)2·2H2O)、氯化亚锡(SnCl2·2H2O)、升华硫(S粉)和十二硫醇为原料,用热注射法合成了Cu2ZnSnS4(CZTS)纳米晶。再将Cu2ZnSnS4纳米晶制成胶体墨水,用旋涂法制备出Cu2ZnSnS4薄膜。用X射线衍射(XRD)仪、拉曼光谱(RS)仪、透射电镜(TEM)、扫描电镜(SEM)、X射线能量色散谱仪(EDS)和紫外-可见光谱(UV-Vis)分光光度计对CZTS纳米晶及薄膜的晶体结构、微观形貌、化学组成及光学性能进行表征,研究了注射温度对纳米晶结构、形貌、晶粒大小以及化学组成的影响以及热处理时间对Cu2ZnSnS4薄膜结构、形貌、化学组成和光学性能的影响。结果表明,在注射温度为180℃时合成的CZTS纳米晶为锌黄锡矿结构,平均粒径为18 nm。在500℃热处理2 h所制备出的薄膜,在可见光范围内其吸收系数高达104cm-1,禁带宽度为1.45 eV。     

Cu2ZnSnS4纳米颗粒及其薄膜的制备与表征

采用热注入法,在油胺(OLA)中合成出Cu2ZnSnS4(CZTS)纳米颗粒,并在玻璃衬底上制备了薄膜,研究了不同合成温度对纳米颗粒生成的影响.通过X射线衍射仪、拉曼光谱仪、透射电子显微镜、扫描电子显微镜、紫外可见分光光度计对所得纳米晶材料的结构与成分、颗粒大小与形貌、光吸收谱进行了测试分析.研究结果表明:采用热注入法的最佳合成温度在260℃左右,该温度下生成的多晶CZTS纳米颗粒尺寸约10 nm,分散性良好,光学禁带宽度约1.5 eV.     

铜锌锡硫纳米颗粒制备的研究进展

Cu2ZnSnS4(CZTS)具有高达104 cm-1的吸收系数,其约1.45eV的禁带宽度与太阳光谱非常匹配,且CZTS所含元素无毒、在地球上含量丰富、价格低廉,适用于辊对辊、丝网印刷等非真空的低成本制造方法,这使得CZTS太阳电池已成为最具产业化发展潜力的薄膜太阳电池之一,因而最近几年倍受关注。低成本的非真空制造方法大都采用CZTS纳米颗粒或其纳米墨水,因此高质量的CZTS纳米粉体的低成本、绿色制备成为CZTS太阳电池器件制造的重要部分。对CZTS纳米颗粒及其纳米墨水的制备方法进行了综述,分析和讨论各种CZTS粉体的制备方法工艺特点及其优缺点,并探讨其发展趋势。     

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。     

新型铜硫系薄膜太阳能电池材料制备的研究进展

薄膜太阳能电池提供了低成本、大面积的无碳发电应用前景，迅猛发展的纳米科技为高转换效率薄膜太阳能电池的低成本制造提供了新途径。新型铜硫系半导体Cu。ZnSnS4（CZTS）薄膜材料具有禁带宽度与太阳辐射匹配性好、光吸收系数大、元素丰度大、价格便宜、无毒等优点，因此将成为最具发展前景的薄膜太阳能电池材料。讨论与分析了CZT...     

微波液相合成法制备Cu_2ZnSnS_4纳米颗粒及其薄膜的研究

采用乙二醇作为溶剂,硫代乙酰胺作为硫源,通过微波液相合成法制备出颗粒大小均一的Cu2ZnSnS4(CZTS)纳米颗粒。采用XRD、Raman、EDS、TEM以及UV-Vis-Nir等表征手段对所制备的纳米颗粒的物相、元素比例、形貌以及光学性能进行了分析。测试结果表明,所制备的CZTS纳米颗粒为(112)择优取向的锌黄锡矿结构,纳米颗粒的平均尺寸约为3.4nm,其光学带隙为1.85eV,呈现出明显的量子尺寸效应导致的光学带隙蓝移现象。将CZTS纳米颗粒制成CZTS墨水并滴涂烘干形成了CZTS薄膜,其XRD和SEM结果表明,所制备的CZTS薄膜具有良好的结晶性,且表面较为致密。光照与暗态的I-V曲线测试表明,所制备薄膜具有明显的光电导效应。     

溶胶-凝胶法制备Cu_2ZnSnS_4薄膜太阳能电池吸收层

以金属盐氯化铜、氯化锌、氯化锡为原料,单乙醇胺和乙二醇甲醚作为溶剂,采用溶胶-凝胶法结合旋涂技术获得前驱体薄膜,分别经120℃和300℃的热板干燥后,在双温区管式炉中,于硫蒸气下硫化制备Cu2ZnSnS4(CZTS)薄膜。利用X射线衍射(XRD)、拉曼光谱仪(Raman)、X射线能量色散谱(EDS)、扫描电子显微镜(SEM)和紫外-可见分光光度计(UV-Vis)等一系列测试设备对样品的结构、各组分的含量、表面形貌和光带隙进行表征分析。研究结果表明,CZTS前驱体薄膜在120℃的热板上干燥后,再经500℃硫化可制备出纯净的CZTS薄膜,禁带宽度接近1.52eV。     

Cu_2ZnSnS_4薄膜的研究进展

Cu2ZnSnS4(CZTS)薄膜太阳能电池具有低成本、高效率、安全无毒等优点,是最具发展前景的太阳能电池之一,近几年来开始受到广泛关注。简要介绍了国内外几种制备Cu2ZnSnS4薄膜的方法,包括蒸发法、溅射法、脉冲激光沉积法、电化学沉积法、喷涂热解法、Sol-gel法、丝网印刷法,并阐述了这几种方法的优点及存在的问题,展望了今后CZTS薄膜的研究方向,认为通过溶剂热或热注入法制备出CZTS纳米晶体后,再通过丝网印刷法或旋涂等法制成CZTS薄膜能降低生产成本,在电池的工业化生产中具有很广阔的应用前景。     

Cu2ZnSnS4/Bi2FeCrO6半导体异质结的脉冲激光沉积法制备及其光电性能

为充分发挥无机铁电氧化物双钙钛矿Bi2FeCrO6(BFCO)的光电特性,选择P型半导体化合物Cu2ZnSnS4(CZTS)作为空穴传输层与BFCO结合,构建半导体异质结.采用脉冲激光沉积法(PLD)制备得到上述两种多元化合物薄膜,SEM,AFM,EDS及XRD测试结果可证明所得产物形貌均匀致密、且符合化学计量比;原位逐层沉积技术可以抑制异质结界面缺陷和杂质的产生.着重研究了沉积温度及不同基底对薄膜性能的影响.采用基于可见光吸收谱的测试和Tauc方法分别估算BFCO和CZTS薄膜的禁带宽度,结果分别为2.23 eV和1.49 eV.研究结果表明:该异质结具有良好的整流特性;当电场强度在0.5 kV/cm到2.0 kV/cm之间时,结构漏电机制符合Schottky发射模型.     

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。     

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.……     

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.……     

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.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to