铜离子掺杂对二氧化钛薄膜光催化性能的影响

采用溶胶-凝胶法在玻璃表面制备了Cu2 掺杂TiO2复合纳米薄膜.掺杂Cu2 的数量和方式及前驱体对TiO2光催化降解甲基橙有不同程度的影响.当合成TiO2前驱体的原料为Ti(OC4H9)4时,预涂一层质量分数(下同)为1.0%的Cu(CH3COO)2水溶液,可使TiO2光催化氧化活性提高53%,最外层掺入Cu2 会减弱TiO2光催化氧化活性.当TiO2的前驱体为工业偏钛酸时,预涂一层1.0%Cu(CH3COO)2水溶液,仅使TiO2光催化氧化活性提高14%.用X射线衍射对纳米薄膜进行表征.Cu2 掺杂会诱导生成金红石相.     

pH对电沉积氧化亚铜薄膜的影响及光催化性能

以导电玻璃为阴极,在不同pH下,从含有0.083mol/LCu(CH3COO)2·H2O、0.22mol/L乳酸的电解液中电沉积合成Cu2O薄膜。研究了电解液pH对Cu2O薄膜晶体择优取向和形貌的影响。结果表明,通过调节电解液pH可合成不同择优取向和形貌的Cu2O薄膜,在pH为7～13内合成的Cu2O薄膜均具有较好的光吸收性。pH=11时,可制得具有(111)取向、结合力强、光催化活性高和稳定性好的Cu2O薄膜。Cu2O薄膜的晶面类型对薄膜催化能力有较大影响,(111)择优取向的Cu2O薄膜的光催化活性最高,反应2.5h后罗丹明B的降解率可达63%。     

铜锌锡硫半导体薄膜材料的制备与表征

采用水热法成功制备了Cu2ZnSnS4(CZTS)半导体材料,通过浸涂法制备了相应的薄膜,并在N2气氛中于400℃对薄膜进行了退火处理.用X射线荧光光谱分析了所得CZTS粉末中各组成元素的含量,并分别用X射线衍射、扫描电子显微镜和紫外-可见-近红外光谱对CZTS薄膜样品的晶体结构、表面形貌和带隙进行了表征.结果表明:所...     

连续离子层吸附反应(SILAR)法制备纳米Cu_2O薄膜

采用低温液相薄膜制备工艺--连续离子层吸附反应(SILAR)法,在玻璃衬底上制备了纳米Cu2O薄膜,考察了工艺参数对薄膜质量和薄膜表面形貌的影响,对薄膜的生长速率与反应溶液浓度、反应温度以及循环次数的关系进行了研究和分析。结果表明,采用连续离子层吸附反应(SILAR)法有利于制备高质量的纳米Cu2O薄膜,连续离子层吸附反应(SILAR)法可以有效去掉疏松的离子,每次循环吸附反应都能使紧密吸附的离子转化成致密的纳米Cu2O薄膜,这样既有利于纳米Cu2O颗粒的生成,同时减少了污染和降低了成本。试验表明,制备纳米Cu2O薄膜的最佳反应温度为70℃,最佳反应溶液浓度均为1 mol/L,纳米Cu2O薄膜的膜厚随着循环次数的增加而增加,循环40次可制得厚度为0.38μm的薄膜。经XRD和SEM测试,所制备的薄膜纯度高,表面平整且致密,Cu2O颗粒大小约为100 nm。     

Effect of periodic precursor on sulfurization process of Cu2ZnSnS4 thin film

In this study, Cu₂ZnSnS₄ (CZTS) thin films were fabricated by periodically sequential depositions of metallic precursors by magnetron sputtering followed by sulfurization. The element compositions, crystal structures, and surface morphologies of the single-period precursor (Zn/Sn/Cu) and four-period precursor (Zn/Sn/Cu/Zn/Sn/Cu/Zn/Sn/Cu/Zn/Sn/Cu) during the sulfurization process were investigated. The experimental results showed that in the initial stage of sulfurization, the single-period precursor had a more efficient reaction with sulfur vapor below 300?°C because of its thicker metal layers. During the process of sulfurization, the CZTS phase first formed in the four-period film at 400?°C, owing to the wide distribution of the internal layer in the periodic thin film. With a further increase in temperature, the crystallinity of CZTS was enhanced and the secondary phases were reduced. A CZTS phase with Cu-poor and Zn-rich composition was confirmed in both thin films after complete sulfurization. The CZTS thin film with a four-period precursor showed a better degree of crystallization, and a single phase of CZTS was obtained more easily than in the single-period thin film. Therefore, using a periodic structure can promote the sulfurization reaction of Cu-Zn-Sn precursors and enhance the properties of CZTS thin films.     

Enhanced Thermoelectric Properties in Cu‐Doped c‐Axis‐Oriented Ca3Co4O9+δ Thin Films

Highly c‐axis‐oriented Ca₃Co_4?xCu_xO_9+δ (x = 0, 0.1, 0.2, and 0.3) thin films were prepared by chemical solution deposition on LaAlO₃ (001) single‐crystal substrates. X‐ray diffraction, field‐emission scanning electronic microscopy, X‐ray photoelectron spectroscopy, and ultraviolet‐visible absorption spectrums were used to characterize the derived thin films. The solubility limit of Cu was found to be less than 0.2, above which [Ca₂(Co_0.65Cu_0.35)₂O₄]_0.624CoO₂ with quadruplicated rock‐salt layers was observed. The electrical resistivity decreased monotonously with increasing Cu‐doping content when x ≤ 0.2, and then slightly increased with further Cu doping. The Seebeck coefficient was enhanced from ~100 μV/K for the undoped thin film to ~120 μV/K for the Cu‐doped thin films. The power factor was enhanced for about two times at room temperature by Cu doping, suggesting that Cu‐doped Ca₃Co₄O_9+δ thin films could be a promising candidate for thermoelectric applications.     

CuO thin films produced for improving the adhesion between Cu and Al2O3 foils in a direct bonded copper (DBC) process

The direct bonded copper (DBC) process was carried out between Cu and Al₂O3 foils and CuO thin films were grown on the surface of Cu foils to reduce the defects produced by the DBC on the surface. CuO thin films were synthesized using a magnetron sputtering system, employing a target of Cu with 99.99% of purity and substrates of Cu foils. The discharge atmosphere for the films growth was (Ar + O₂). Once the coatings were grown, coated and uncoated Cu foils were joined at both sides (one on the top and the other at the button) of the alumina foil using the traditional direct bonded process. The Atomic concentration, chemical composition and bonding configuration of both cases were studied by X-ray photoelectron spectroscopy (XPS), finding Metallic Cu, Cu₂O and Cu–O bonds; furthermore, the atomic concentration analysis showed that coated Cu foil exhibited lower oxygen percentage, compared with uncoated one. The study of the surface defects was carried out using scanning electron microscopy (SEM) showing that the Al₂O3 ceramic was better pasted with the Cu foil including the CuO thin film.     

Unique molecular aggregation of novel naphthalocyanine (near IR absorbing dye)

A series of organic-soluble naphthalocyanine derivatives (Y_mMNcX₄) have been synthesized. Their spectroscopic properties in organic solutions and in thin films were studied. MNcX₄ such as MNc(t-Bu)₄ (5a-5c) and MNc(On-Bu)₄ (5j) formed H-aggregates even in dilute solutions. MNc(CO₂R')₄ (5d-5i) had much stronger H-aggregation properties compared with those ofMNc(t-Bu)₄ and MNc(On-Bu)₄. Especially, MNc(CO₂R')₇ complexes (M=Cu, Pd and Ni) existed exclusively without monomers in the aggregated state even in highly dilute solutions. MNcX₄, which has strong H-aggregation properties, showed merely H- aggregate absorption maxima in thin films. In contrast, Y₂MNcX₄ (4), which has sterically hindered Y groups, showed monomerically pure characteristics in solution. However, thin films of Y₂MNcX₄ have a J-type molecular arrangement, exhibiting a red shift of Q-band absorption. The monomeric properties of Y₂MNcX₄ in solutions and J-type molecular arrangement in thin films arise from steric hindrance of two Y groups, such as R₃SiO-in Y₂MNcX₄, which prevents strong H-aggregation of naphthalocyanine.     

CZTSe solar cells prepared by electrodeposition of Cu/Sn/Zn stack layer followed by selenization at low Se pressure

Cu₂ZnSnSe₄ (CZTSe) thin films are prepared by the electrodeposition of stack copper/tin/zinc (Cu/Sn/Zn) precursors, followed by selenization with a tin source at a substrate temperature of 530°C. Three selenization processes were performed herein to study the effects of the source of tin on the quality of CZTSe thin films that are formed at low Se pressure. Much elemental Sn is lost from CZTSe thin films during selenization without a source of tin. The loss of Sn from CZTSe thin films in selenization was suppressed herein using a tin source at 400°C (A2) or 530°C (A3). A copper-poor and zinc-rich CZTSe absorber layer with Cu/Sn, Zn/Sn, Cu/(Zn + Sn), and Zn/(Cu + Zn + Sn) with metallic element ratios of 1.86, 1.24, 0.83, and 0.3, respectively, was obtained in a selenization with a tin source at 530°C. The crystallized CZTSe thin film exhibited an increasingly (112)-preferred orientation at higher tin selenide (SnSe _x ) partial pressure. The lack of any obvious Mo-Se phase-related diffraction peaks in the X-ray diffraction (XRD) diffraction patterns may have arisen from the low Se pressure in the selenization processes. The scanning electron microscope (SEM) images reveal a compact surface morphology and a moderate grain size. CZTSe solar cells with an efficiency of 4.81% were produced by the low-cost fabrication process that is elucidated herein.     

Cu基电沉积ZnO薄膜光催化降解甲基橙研究

以Zn(NO3)2水溶液为电解液,在Cu基体上电沉积ZnO薄膜,用X-射线衍射和扫描电子显微镜对其结构及形貌进行了表征。以甲基橙为目标有机污染物,研究了pH、SO42-和NO3-以及外加阳极偏压对ZnO薄膜光催化性能的影响。实验结果表明,在酸性条件下,可以获得更高的降解率;SO42-的存在明显地抑制了降解过程,而NO3-则有着很大的促进作用;外加阳极偏压在一定程度上改善了光催化降解效果。     

Solution-based synthesis of dense,large grained CuIn(S,Se)2 thin films using elemental precursor

Compared with the expensive and complicated vacuum techniques, the solution-based process to deposit I-III-VI₂ chalcogenide thin films (I=Cu, III=In or Ga, VI=S or Se) has attracted great interests due to its lower cost, higher scalable production and better application in flexible substrate. Herein, a low-toxic and high-active mixture solvent comprised of 1, 2-ethanedithiol and 1,2-ethylenediamine is utilized to dissolve elemental Cu, In and S powders at 60 °C, forming the CuInS₂ (CIS) precursor solution. After spin coating and annealing in a both Ar gas and selenium atmosphere, a dense and large-grained chalcopyrite CuIn(S,Se)₂ (CISSe) thin films with a close-packed grain size of ~800 nm are prepared, eliminating a undesired fine fine-grained bottom layer. In addition, the selenization temperature of the CISSe thin films is also discussed, which influences the phase composition, crystallinity and morphology of CISSe thin films. Photovoltaic device of the CISSe-based thin films is fabricated, obtaining a power conversion efficiency of 6.2% with an active cell area of 0.5 cm² under AM 1.5 illumination.     

Relation between electrical properties of aerosol-deposited BaTiO3 thin films and their mechanical hardness measured by nano-indentation

ABSTRACT: To achieve a high capacitance density for embedded decoupling capacitor applications, the aerosol deposition (AD) process was applied as a thin film deposition process. BaTiO3 films were fabricated on Cu substrates by the AD process at room temperature, and the film thickness was reduced to confirm the limit of the critical minimum thickness for dielectric properties. As a result, the BaTiO3 thin films that were less than 1-μm thick showed unstable electric properties owing to their high leakage currents. Therefore, to overcome this problem, the causes of the high leakage currents were investigated. In this study, it was confirmed that by comparing BaTiO3 thin films on Cu substrates with those on stainless steels (SUS) substrates, macroscopic defects and rough interfaces between films and substrates influence the leakage currents. Moreover, based on the deposition mechanism of the AD process, it was considered that the BaTiO3 thin films on Cu substrates with thicknesses of less than 1 μm are formed with chinks and weak particle-to-particle bonding, giving rise to leakage currents. In order to confirm the relation between the above-mentioned surface morphologies and the dielectric behavior, the hardness of BaTiO3 films on Cu and SUS substrates was investigated by nano-indentation. Consequently, we proposed that the chinks and weak particle-to-particle bonding in the BaTiO3 thin films with thicknesses of less than 0.5 μm on Cu substrates could be the main cause of the high leakage currents.     

Cu_3N薄膜制备及其性能研究

Cu3N薄膜的晶面取向、沉积速率、电学特性等性质除与制备方法有关外,还和制备工艺参数有很大关系。溅射法制备Cu3N薄膜工艺参数主要有,混合气体(N2+Ar)中氮气分压比r、基底温度T(℃)、溅射功率P(W)。为了研究Cu3N薄膜的性能与其制备工艺参数之间关系,本文采用反应射频磁控溅射法,在玻璃基底上成功制备了Cu3N薄膜,并研究了工艺参数对其晶面取向、膜厚、电学性能、沉积速率的影响。     

UV photodetection properties of pulsed laser deposited Cu-doped ZnO thin film

Nanocrystalline undoped and 2 at% copper (Cu) doped zinc oxide (ZnO) thin films were successfully grown onto SiO₂/n-Si substrates at 600 °C by using pulsed laser deposition (PLD) technique. The influence of Cu incorporation on structural, surface morphological, elemental composition and UV detection properties of ZnO film was investigated. X-ray diffraction studies of thin films show that they are polycrystalline and have a hexagonal wurtzite structure; however, Cu doping improves the preferential orientation along c-axis. The chemical state of constituent elements was analysed by X-ray photoelectron spectroscopy (XPS). It indicates the presence of Cu ions in the doped film that exist in a mixed univalent and bivalent state. FE-SEM observations support the crystallographic results. The effective incorporation of Cu ions into the lattice of the ZnO nanostructure without changing its wurtzite structure was confirmed by an energy dispersive X-ray spectroscopic analysis (EDX). The UV photodetection characteristics of both films were further studied in metal-semiconductor-metal (MSM) planar configurations at room temperature and are found to be greatly influenced by Cu doping. The incorporation of Cu into ZnO lattice increases the resistivity of thin film; which leads to lower dark current. As a result, the Cu-doped ZnO film based UV PD demonstrates improved UV sensitivity of about 66.92 upon 2 mW/cm² UV illumination at 365 nm peak wavelengths and 5 V applied bias. The reproducible UV detection performance of MSM devices was also ensured by periodically switching UV light on and off at fixed time intervals.     

A new method for measuring wetness of flowing steam based on surface plasmon resonance

Stacked precursors of Cu-Zn-Sn-S were grown by radio frequency sputtering and annealed in a furnace with Se metals to form thin-film solar cell materials of Cu₂ZnSn(S,Se)₄ (CZTSSe). The samples have different absorber layer thickness of 1 to 2 μm and show conversion efficiencies up to 8.06%. Conductive atomic force microscopy and Kelvin probe force microscopy were used to explore the local electrical properties of the surface of CZTSSe thin films. The high-efficiency CZTSSe thin film exhibits significantly positive bending of surface potential around the grain boundaries. Dominant current paths along the grain boundaries are also observed. The surface electrical parameters of potential and current lead to potential solar cell applications using CZTSSe thin films, which may be an alternative choice of Cu(In,Ga)Se₂. PACS number: 08.37.-d; 61.72.Mm; 71.35.-y     

Nanoscale observation of surface potential and carrier transport in Cu2ZnSn(S,Se)4 thin films grown by sputtering-based two-step process

Stacked precursors of Cu-Zn-Sn-S were grown by radio frequency sputtering and annealed in a furnace with Se metals to form thin-film solar cell materials of Cu₂ZnSn(S,Se)₄ (CZTSSe). The samples have different absorber layer thickness of 1 to 2 μm and show conversion efficiencies up to 8.06%. Conductive atomic force microscopy and Kelvin probe force microscopy were used to explore the local electrical properties of the surface of CZTSSe thin films. The high-efficiency CZTSSe thin film exhibits significantly positive bending of surface potential around the grain boundaries. Dominant current paths along the grain boundaries are also observed. The surface electrical parameters of potential and current lead to potential solar cell applications using CZTSSe thin films, which may be an alternative choice of Cu(In,Ga)Se₂.PACS number: 08.37.-d; 61.72.Mm; 71.35.-y     

氧化亚铜在太阳能电池、光催化领域的研究进展

作为半导体光电功能材料,Cu2O薄膜和纳米材料由于具有独特的能带结构和优异的性能,在电子信息、能源、环境保护等领域具有重要的应用前景。介绍了Cu2O薄膜与纳米材料的制备方法及其在太阳能电池和光催化领域的应用。分析了目前存在的问题,并提出今后研究的对策。     

CIGS absorbing layers prepared by RF magnetron sputtering from a single quaternary target

Cu(In_1−xGa_x)Se₂ (CIGS) thin films were prepared by RF magnetron sputtering from a single quaternary target at multiple processing parameters. The structural, compositional, and electrical properties of the as-deposited films were systematically investigated by XRD, Raman, SEM, and Hall effects analysis. The results demonstrate that by adjusting the processing parameters, the CIGS thin films with a preferential orientation along the (112) direction which exhibited single chalcopyrite phase were obtained. The films deposited at relatively higher substrate temperature, sputtering power, and Ar pressure exhibited favorable stoichiometric ratio (Cu/(In+Ga):0.8–0.9 and Ga/(In+Ga):0.25–0.36) with grain size of about 1–1.5 µm, and desirable electrical properties with p-type carrier concentration of 10¹⁶−10¹⁷ cm⁻³ and carrier mobility of 10–60 cm²/Vs. The CIGS layers are expected to fabricate high efficiency thin film solar cells.     

新型纳米光催化薄膜的结构设计与应用研究

采用溶胶-凝胶法分别制备了TiO2/ZrO2、TiO2/ZrTiO4、TiO2/SiO2等异质结构纳米薄膜.本文对形成溶胶的各成分配比、粘度以及薄膜样品的热处理工艺等进行了探讨,同时用喷涂法在瓷砖上成功制备光催化薄膜,用SEM对薄膜的外貌特征进行了表征,并利用紫外-可见分光光度计研究了薄膜吸收光谱的变化,用分光光度法研究了异质结构薄膜对甲基橙溶液的降解,探讨了过渡层对薄膜的光催化效率和抗失活稳定性的影响.结果表明,TiO2/ZrO2、TiO2/ZrTiO4薄膜中的晶粒尺寸减小,薄膜的光催化活性和抗失活稳定性均有较大提高,并可以用工厂方法制备大面积薄膜.     

Study of Cu-based Al-doped ZnO multilayer thin films with different annealing conditions

AZO/Cu/AZO multilayer thin films produced under different annealing conditions are studied in this paper, to examine the effects of atmosphere and annealing temperature on their optical and electrical properties. The multilayer thin films are prepared by simultaneous RF magnetron sputtering (for AZO) and DC magnetron sputtering (for Cu). The thin films were annealed in a vacuum or an atmosphere of oxygen at temperatures ranging from 100 to 400 °C in steps of 100 °C for 3 min. High-quality multilayer films (at Cu layer thickness of 15 nm) with resistivity of 1.99×10⁻⁵ Ω-cm and maximum optical transmittance of 76.23% were obtained at 400 °C annealing temperature in a vacuum. These results show the films to be good candidates for use as high quality electrodes in various displays applications.