Preparation of wide gap Cu(In,Ga)S2 films on ZnO coated substrates

We have prepared Cu(In,Ga)S₂ films at growth temperatures from 300 °C to 580 °C with a homogeneous gallium depth distribution (estimated band gap 1.67 eV) onto soda lime glass (SLG) substrates with one of three different kinds of back contact: Mo(1000 nm), ZnO(500 nm), and Mo(30 nm)/ZnO(500 nm), respectively. We have also investigated the depth profiles of Zn and Na (diffused from SLG) in Cu(In,Ga)S₂ films by secondary ion mass spectroscopy (SIMS). The efficiency of solar cells on Mo increases with increasing growth temperature. It is higher on Mo/ZnO than on ZnO, and increases from 350 °C to 450 °C, then decreases above 450 °C. It was observed by SIMS that the amount of Zn in Cu(In,Ga)S₂ on Mo/ZnO is lower than it is on ZnO up to 450 °C, and a large amount of Zn diffuses into absorbers over 450 °C, which contributes to decreasing efficiency. The amount of Na in the back contact increases with growth temperature. The depth distribution of Na in Cu(In,Ga)S₂ films on Mo is almost constant in the order of 10¹⁷-10¹⁸ cm^− 3, on ZnO and Mo/ZnO the Na concentration increases towards the surface and is in the range of 10¹⁵-10¹⁷ cm^− 3.     

CIGS thin-film solar cells on steel substrates

Steel foil is an attractive candidate for use as a flexible substrate material for Cu(In_x,Ga_1 − x)Se₂ solar cells (CIGS). It is stable at the high temperatures involved during CIGS processing and is also commercially available. Stainless chromium (Cr) steel is more expensive than Cr-free steel sheets, but the latter are not stable against corrosion. We processed CIGS solar cells on both types of substrates. The main problem arising here is the diffusion of detrimental elements from the substrate into the CIGS absorber layer. The diffusion of iron (Fe) and other substrate elements into the CIGS layer was investigated by Secondary Ion Mass Spectrometry (SIMS). The influence of the impurities on the solar cell parameters was determined by current voltage (JV) and external quantum efficiency (EQE) measurements. A direct correlation between the Fe content in the CIGS layer and the solar cell efficiency was found. The diffusion of Fe could be strongly reduced by a diffusion barrier layer. Thus we could process CIGS solar cells with a conversion efficiency of 12.8% even on Cr-free steel substrate.     

Effects of iodine on the initial growth of MOCVD Cu on MPTMS monolayer surface at a low temperature of 110 °C

Cu was deposited by chemical vapor deposition (CVD) on self-assembled monolayers of a 3-mercapto-propyl-trimethoxy-silane (MPTMS)-coated SiO₂ substrate using (hfac)Cu(DMB) and C₂H₅I as precursors at 110 °C. The effects of iodine addition on the initial growth of Cu were investigated by scanning electron microscopy (SEM). For comparison, Cu was deposited without iodine on the MPTMS monolayer. The low temperature deposition of Cu without iodine showed that the initial growth of Cu particles is limited by the direct flux of Cu precursors on the growing Cu surface, which continues until active coalescence occurs. This results in a very low growth rate (1 Å/s) of Cu particles at the initial stage of particle growth. The addition of iodine significantly enhanced the surface-diffusion of Cu adatoms over the MPTMS surface and allowed the facile dissociation of Cu(hfac) adsorbed on the Cu surface. These two effects increased the growth rate of Cu particles to approximately 13 Å/s. However, the root square time dependence of the growth rate of Cu particles suggests that the iodine-enhanced surface diffusion of Cu adatoms is a major contributor to the increased growth of Cu particles.     

纳米Cu_2Se的制备及其生长机理分析

采用一种新的合成技术,在复合氢氧化物熔融体中,以CuCl2·2H2和Se粉为原料在200℃下合成了Cu2Se纳米晶体,X射线衍射谱表明合成的Cu2Se纳米晶体属立方晶系结构,格点对称群为Fm3m(225),格点参数a=0.5765nm.扫描电子显微镜(SEM)和透射电子显微镜(TEM)图表明Cu2Se纳米晶体为厚度为10～20nm,宽度为200～300nm的片状结构.生长时加入少量的水会导致棒状非晶产生,水量越多棒状非晶的尺寸越大,使得Cu2Se晶体的均匀性和品质变差.根据配位多面体生长机理模型,计算了生长基元的稳定能,并探讨了在复合氢氧化物熔融中纳米Cu2Se晶体的形成机理.     

电化学沉积太阳电池用CuInSe2和Cu(In,Ga)Se2薄膜的研究进展

综述了电化学沉积太阳电池用CuInSe2(CIS)和Cu(In,Ga)Sez(CIGS)薄膜的研究和发展;对CIS和CIGS预制层的电化学沉积路线,包括一步沉积、分步沉积和特种电沉积的研究进展进行了详细的评述;综述了电沉积预制层的后处理,包括退火、化学处理和PVD调整成分的研究状况.回顾了基于电化学沉积的CIS和CIGS太阳电池研究的发展过程,并介绍了目前实验室和产业化研究的最新成果,指出了存在的问题并展望了其发展趋势.     

铜离子印迹磁性复合吸附剂的性能研究

为了提高吸附剂对特定重金属离子的吸附容量,采用离子印迹技术合成了一种具有磁性的铜离子印迹复合吸附剂(Cu(Ⅱ)-IMB).通过SEM、能谱、XRD、FTIR、振动样品磁强计(VSM)表征方法对Cu(Ⅱ)-IMB及其合成原料进行表征,对Cu(Ⅱ)-IMB吸附选择性和其他物理性质进行了研究.结果表明,Cu(Ⅱ)-IMB对印迹的Cu(Ⅱ)具有高的选择吸附性能,与非印迹磁性复合吸附剂(NIMB)、壳聚糖交联菌丝体吸附剂(CMB)和菌丝体吸附剂(MB)相比吸附容量可分别提高24%,33%和54%.Cu(Ⅱ)-IMB重复使用5次后,吸附容量比原来降低14%.该新型吸附剂具有良好的机械强度和重复使用性,具有磁性能够迅速从吸附后的溶液中分离出来,成本低廉能够大量生产.     

高比表面积SiO_2为基质的含N复合分离材料的制备及其吸附性能

制备了PEI/SiO2复合分离材料,用红外光谱鉴定了其-N基团的存在,用SEM观察了其表面结构,并且用树脂吸附铜离子量来表征了其结合PEI的量.结果表明,复合分离材料对于铜离子的吸附速率很快,在0.5～0.7h就已经达到了饱和,静态最大吸附容量为47.1mg/g树脂;同时树脂具有再生性能,经过10次的解吸-吸附试验后,其吸附容量降至42.5mg/g树脂.     

等离子发射光谱法测定六硼化镧中铁、钙、镁、铬、锰、铜

采用等离子发射光谱法测定六硼化镧中铁、钙、镁、铬、锰、铜,各元素测定范围：0．0001％～0．10％,方法回收率在91．0％～110％;相对偏差小于10％。方法准确度高,精密度好,结果令人满意。     

丙酮酸改性壳聚糖的制备及应用

利用壳聚糖C2位上活泼氨基与丙酮酸进行席夫碱反应,制取丙酮酸改性壳聚糖(简称为PCTS)。实验结果表明其最佳的合成条件为:1.8g溶胀的壳聚糖与1.48g丙酮酸在pH=4～5反应4h后,加入1.7g NaBH4反应1.5h,合成的1.6g PCTS,取代度可达88.14%。结果显示0.1g的PCTS吸附0.1g/L的Cu(Ⅱ)和Zn(Ⅱ),其吸附率分别可达100%和99.29%;PCTS对NO2也有一定的清除作用,11mg/ml的取代度为85.79% PCTS对NO2的清除率可达50.57%。     

Preparation and mechanical properties of a new Zr–Al–Ti–Cu–Ni–Be bulk metallic glass

In this paper, a new Zr₃₇Al₁₀Ti_12.5Cu_11.25Ni₉Be_20.25 bulk metallic glass is reported. The present alloy was prepared by water quenching in a silica tube of φ10×85 mm. The amorphicity of the quenched bulk samples was examined using X-ray diffraction analysis and optical microscopy. The thermal stability was evaluated by differential scanning calorimetry (DSC) at a heating rate of 10 K/min. The characteristic data of the bulk metallic glass are presented, including glass transition temperature (T_g) and crystallization temperature (T_x). Results show that the present alloy exhibits large glass forming ability. For comparison with the well-known Zr–Ti–Cu–Ni–Be metallic glass, it was found that aluminum has a little effect on the vitrification of the present alloy but influences physical properties. Specifically, Al enhances the Young's modulus by 21.4% and Vickers hardness by 20% and reduces density by 7.2%.