Electrodeposition Of Cu Research Articles

Electrodeposition of copper – tin alloys from glycol electrolytes

Stable ethylene glycol (EG) and propylene glycol (PG) electrolytes containing СuCl2 · 2H2O, SnCl4 · 5H2O and Trilon B have been developed, which provide electrodeposition of Cu – Sn alloy with tin content varying from 34 to 52 at. % in case of EG and from 51 to 91 at. % in case of PG electrolytes. It is found that the coatings contain phases of Cu6Sn5 и Cu10Sn3 intermetallic compounds, and metallic tin is also present in case of its highest content in the alloy. It is revealed that tin content can be simply varied by the change of current density or concentrations of tin and copper compounds in glycols. The effect of electrolyte composition, deposition conditions, a nature of a substrate on the coatings deposition rate (in the limits of 0.9‒2.9 μm ∙ h‒1), total metal current efficiency (from 40 to 95 %), the ratio of metals in the alloy (from 34 to 91 at. %), its phase composition and microstructure is determined. The conditions for the deposition of Cu – Sn alloy close to the eutectic composition have been found.

Electrochemical detection combined with machine learning for intelligent sensing of maleic hydrazide by using carboxylated PEDOT modified with copper nanoparticles.

Amethod for intelligent data analysis was designed by combining electrochemical sensing with machine learning (ML). Specifically, a voltammetric sensor is described for determination of the phytoinhibitor maleic hydrazide in crop samples. Carboxyl-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT-C4-COOH) was electro-synthesized in aqueous micellar solution by direct anodic oxidation of its monomer. A nanosensor was then prepared by placing copper nanoparticles (CuNPs) on the PEDOT-C4-COOH film via electro-deposition of Cu (II) from aqueous micellar solutions. An artificial neural network (ANN) served as a powerful ML model to realize intelligent data analysis and smart transformation for digital output. Different established regression methods were selected for evaluating the ANN-based method that was found to be superior to known methods. The sensor has a wide working range (from 0.06-1000μM), a low limit of detection (10nM), good stability, selectivity and practicality. The method was applied to the determination of maleic hydrazide in (spiked) samples of onion, rice, potato and cotton leaf. Satisfactory results demonstrate that the feature of simultaneous data acquisition and analysis is highly attractive. Graphical abstract Schematic representation of an electrochemical sensor based on carboxyl-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT-C4-COOH) and copper nanoparticles (CuNPs) by differential pulse voltammetry (DPV) to detect maleic hydrazide (MH). PEDOT-C4-COOH was electro-synthesized in 0.1M LiClO4 aqueous micellar solution with 0.1M sodium dodecyl benzene sulfonate (SDBS) by amperometry(CA). CuNPs was prepared by cyclic voltammetry (CV).

Electrodeposition of Cu–SWCNT Composites

Single walled carbon nanotubes (SWCNTs) are used as a component of a plating solution of CuSO4 for direct current electrodeposition of Cu–SWCNT composites with varying nanotube proportions without the use of either a surfactant, a dispersing agent, or functionalization of the SWCNTs. The Cu–SWCNT composites are characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The composites are comprised of metallic Cu and SWCNTs with minor oxide impurities, as well as the residual (Fe) catalyst from the unpurified SWCNTs, in addition to displaying nanotube-mediated morphological differences. EDX analysis of carbon (wt%) is close to quantitative with respect to the wt% of SWCNTs added to the electrolysis solution. The presence of SWCNTs decreases the oxidation of the copper, as well as changing the identity of the oxide from CuO, for electrolysis of Cu, to Cu2O. Hard adherent Cu–SWCNT coatings are prepared by the addition of Cu powder to the electrolysis solution. The approach described in this paper will enable controlled synthesis of metal-nanomaterial composites that can potentially be processed further into high ampacity electrical conductors.

Mechanical Characterization of Close Cell Aluminum Foams Reinforced by High Voltages Electro-deposition

The parameters for the electro-deposition of Cu were optimized in order to increase the compressive properties of close cell aluminum. Different values of deposition voltages and times were considered to vary the amount of deposited Cu. The surface morphology of the coating was observed by SEM and the compressive properties were evaluated by MTS. The results show that the coating is more homogeneous and compact with increasing voltage in a certain range, and beyond which, the coating quality decreases apparently. The reason is dedicated to the discharge rate of Cu2+ and nucleus formed in unit time. The compression results show three experienced stages: elastic deformation stage, collapse deformation stage and densification stage. After the electro-deposition of Cu, the elasticity modulus is increased obviously and the platform stress is also increased. Under the same strain, the stress of the aluminum foam with coating is reinforced comparing with the aluminum foam without coating. Furthermore, the platform area is widened apparently. In addition, Cu-SiC nanocomposite coatings are electrodeposited in alumium foams for further improving the mechanical characterization.

Cu(In,Ga)Te2 film growth by a two-stage technique utilizing rapid thermal processing

Cu(In,Ga)Te2 (CIGT) thin films doped with Na were grown using a two-stage technique. During the first stage of the process precursor layers were formed over Mo coated stainless steel foil substrates by electrodeposition of Cu, In and Ga and evaporation of a NaF film as a dopant and Te. During the second stage, the foil/Mo/(Cu, In, Ga)/NaF/Te stacks were reacted by rapid thermal processing. The ramp rate to the reaction temperature of 600 °C was changed between 0.5 and 10 °C s−1. Resulting compound layers were analyzed to evaluate the effect of the temperature ramp rate on film quality. It was found that a secondary phase of InTe that was detected in films reacted at ramp rates of 0.5–5 °C s−1 was not present for the films reacted at a ramp rate of 10 °C s−1. Film morphology of the fast ramp rate sample showed improved crystallinity and grain size, which was superior compared to others. Gallium gradation was detected through all the layers irrespective of the temperature ramp rate, surface of the films being more In-rich.

Inhibition Effect of CTAB on Electrodeposition of Cu in Micro Via: Experimental and MD Simulation Investigations

The integrated circuits (IC) device keep diminishing in size, resulting in that the stacking type of packaging technologies gains increasing attention in the IC device manufacturing industry. By providing vertical interconnection paths for the chips, the through silicon via (TSV) is the key interconnection structure in the stacking packaging. In the fabricating process of TSV, non-defect filling of the micro via is difficult to achieve. Adding additives in the electrolyte is a common way to eliminate defects from the micro via. In this study, a singular additive, namely Cetyltrimethyl Ammonium Bromide (CTAB), is added in the electrolyte to achieve non-defect filling of the micro via. Through electrochemical analysis, it is found that the CTAB shows a significant inhibition effect on the electrodeposition rate. The adsorption behavior of the additive is investigated by MD method. The simulation results indicate that the adsorption behavior of the CTAB to the cathode is related to the surface charge of the cathode. In addition, a competitive adsorption is observed between the CTAB and the Cu2+ ions on the charged surface of the cathode.

Electrolyte Effects in Reversible Metal Electrodeposition for Optically Switching Thin Films

Thin films that electronically switch between optical states are of interest for a number of applications including dynamic windows, switchable sunglasses, and optical gating devices. We report thin films based on the reversible electrodeposition of Cu and Au on tin-doped indium oxide (ITO) electrodes modified with Pt nanoparticles that switch between transparent and opaque states. By systematically studying the voltammetry of electrolytes with various compositions, we determine that Cu and Au synergistically facilitate optically reversible metal electrodeposition and that comparable electrolytes with either metal alone do not give rise to reversible systems. Furthermore, we demonstrate that halides in the electrolyte promote optically reversible metal electrodeposition by accelerating both the metal electrodeposition and dissolution processes.

Electrochemical and in situ SERS study of the role of an inhibiting additive in selective electrodeposition of copper in sulfuric acid

The role of an inhibiting additive in selective copper (Cu) deposition was investigated using linear sweep and cyclic voltammetry and in situ SERS. Both the normalized SERS peak intensity of Basic Red 12 and the Cu deposition current showed hysteresis. These results indicate that Basic Red 12 desorbs or decomposes on the surface during electrodeposition of Cu. Therefore the concentration of Basic Red 12 on the patterned area decreases more than that on the flat area. This inhomogeneity of concentration leads to the preferential growth of Cu on the patterned area.

Pulse Electrodeposition of Cu through-Silicon-Via (TSV) with Surface Suppressor

In recent years, many researches have been focused on the miniaturization of the integrated circuit (IC) feature size to improve the performance of semiconductor devices. However, we are facing the problems such as physical limit of the miniaturization and then increasing processing cost. To overcome these problems the Through-Si-Via (TSV) interconnection, a kind of the 3D interconnection, is a promising technology that could achieve high density, lower energy consumption and high performance in the IC. Since the TSV filling process is costly in the entire TSV process, the TSV filling process which the Cu electrodeposition for TSV is one of key processes. The TSV bottom-up filling which the filling of Cu from the bottom to the top of via with suppressed lateral growth is the solution to ensure a void free filling in high aspect ratio TSV. The bottom-up filling could be achieved by using additives like a suppressor and an accelerator in the electrolyte. In a theoretical model, the suppression breakdown at the bottom of TSV cause the bottom-up filling of TSV. Simultaneous desorption of suppressor by high potential due to ion depletion in the via bottom leads focus of current at the via bottom. Due to adsorption/desorption behavior of the suppressor, the bottom-up TSV filling could be achieved by only using the suppressor.1-3 Furthermore, it was reported that the suppressor at the sidewall is replaced by the accelerator and then the bottom-up filling performance was degraded.3 Lu et al. introduced the nanotwin Cu thin film, which had been attained with pulse electrodeposition.4 Mechanical properties of the Cu thin film is significantly enhanced by highly dense coherent twin boundaries without the degradation of electrical conductivity. Because it could effectively block the dislocation motion without interrupting the migration of electrons.4 The mechanical property of TSV interconnection such as thermal behavior is important as well as the electrical property including electrical conductivity for improvement TSV performance. Therefore, the nanotwin Cu is proper for the TSV interconnection. In this study, nanotwin Cu was applied to fill into high aspect ratio of via (diameter = 5 µm, depth = 60 µm) with pulse current conditions. The deposition condition between direct current and pulse current was compared to observe the filling characteristics. The mechanical properties as the thermal expansion behavior, which is critical to adopting integrated devices, of nanotwin Cu were investigated. As a result, the results with pulse current condition showed obvious improved the TSV filling property than direct current condition. 1. T. P. Moffat and D. Josell, J. Electrochem. Soc., 159, D208 (2012). 2. T. Moffat and D. Josell, Journal of The Electrochemical Society, 159, D208 (2012). 3. L. Yang, A. Radisic, J. Deconinck, and P. M. Vereeckena, J. Electrochem. soc., 160, D3051 (2013). 4. L. Lu, Science, 304, 422-426 (2004).

Electrodeposition of Mo/Zn/Cu/Sn Unconventional Stack for CZTS Thin Films Synthesis

The interest towards Cu2ZnSnS4 (CZTS) photoactive material relies into the abundancy and non-toxicity of the elements considered [1, 2]. Among the fabrication routes investigated in literature, the single layer approach, consisting in the electrodeposition of Cu, Sn, Zn layers followed by reactive annealing, is the most promising showing higher efficiency devices than coelectrodeposition-based ones. The typical stack order is Mo/Cu/Sn/Zn, where the electrodeposition of the most noble metal is followed by intermediate and subsequently by the least noble one [2, 3]. This layer sequence is strongly connected to water-based electrolytes where pH dependence limits the possible stack combinations. However, it was reported that the ideal layer stacking, fabricated by means of sputtering, would consider to have Zn as first layer to avoid its loss during the annealing treatments (high vapor pressure) and to promote a good interface with Mo [4]. In the present work, a traditional electrodeposition-annealing route of an unconventional stack order (Mo/Zn/Cu/Sn) is proposed by employing an organic solution based on ethylene glycol for the copper electrodeposition while an aqueous one for zinc and tin depositions. The electrochemical behaviour of the copper solution was investigated by means of cyclic voltammetry (CV) and linear sweep voltammetry. Galvanostatic approach was investigated, employing of Hull cell as preliminary test. Soft and reactive (sulfur atmosphere) annealing were performed; the formation of kesterite were verified by means of Raman spectroscopy. CZTS thin films were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD); photoelectrochemical characterization was performed to evaluate the photoactivity.

Effects of Enhanced Hole Mobility on Electrochemically Synthesized p-Type CuAlO2 Films for Photoelectrochemical Hydrogen Production from Water

Delafossite CuAlO2 photoelectrodes are synthesized via the electrodeposition of Cu(II) and Al(III) onto fluorine-doped tin oxide (FTO) substrates in water and dimethylsulfoxide (DMSO) solvents, followed by annealing in air and Ar. The surface property, crystalline structure, and photoelectrochemical (PEC) performance of as-synthesized samples are significantly affected by the synthetic condition. Optimized CuAlO2 electrodes (synthesized in DMSO and annealed in Ar) possess suitable energetics for H2 production under sunlight (an optical bandgap of ~1.4 eV and a conduction band level of -0.24 VRHE). They exhibit a photocurrent onset potential of ~+0.9 VRHE along with a Faradaic efficiency of ~70% at +0.3 VRHE in an alkaline solution (1 M KOH) under simulated sunlight (AM 1.5; 100 mW×cm-2). The addition of sacrificial hole scavengers (sulfide and sulfite) significantly improves the PEC performance of CuAlO2 by a factor of eight, along with providing a Faradaic efficiency of ~100%. This indicates that the hole transfer limits the overall PEC performance. This issue is addressed by employing a ~150 nm-thick Au film-coated FTO substrate for the CuAlO2 deposition. In the absence of hole scavengers, the H2 production with the Au-underlain CuAlO2 photoelectrode (Au/CuAlO2) was three-fold higher than that with bare CuAlO2, while the Faradaic efficiencies at +0.3 and +0.55 VRHE were ~100%. The time-resolved photoluminescence emission decay spectra of the CuAlO2 and Au/CuAlO2 confirmed the facilitated charge transfer in the latter.

Effect of Sonochemical Treatment Modes on the Electrodeposition of Cu–Sn Alloy from Oxalic Acid Electrolyte

Methods of scanning electron microscopy, potentiodynamic polarization, and X-ray diffraction analysis were used to study the kinetic features of the electrodeposition process of the copper–tin alloy from an oxalic acid electrolyte and analyze the structure, composition, and luster of coatings formed under sonochemical treatment conditions at varied power of the ultrasonic field and current load. The ultrasonic treatment with power of 8–40 W dm–3 makes it possible to 2–8 times intensify the cathodic process and obtain coatings containing 10–15 wt % tin with luster of 20–40%. The specific content of tin in a coating being formed is nearly independent of the ultrasound power and grows with increasing the cathodic current density.

Development of Superstrate CuInGaSe2 Thin Film Solar Cells with Low-Cost Electrochemical Route from Nonaqueous Bath

Electrodeposition of Cu(In,Ga)Se2 (CIGS) thin film is an attractive approach for the development of highly efficient low-cost solar cells. This work focuses on the effects of various electrodeposition parameters on the growth and properties of CIGS layers. The films deposited at −0.9 V tend to drive the growth of CIGS favoring (112) crystal orientation, whereas the films deposited at −1.6 V show the orientation along (220)/(204). Interplanar distances corresponding to (112) and (204/220) planes could be observed in the high resolution transmission electron microscopy (HRTEM) images of the respective films, confirming the dependence of the texture on the deposition potential. Films with larger grains could be grown by maintaining higher temperature (130 °C) during the deposition of layers. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Cu+, In3+, Ga3+, and Se2– valence states in the CIGS layers prepared at −0.9 and −1.6 V. The film deposited at −1.6 V with (220/204) orientation showed hig...

Applying the protective CuMn2O4 spinel coating on AISI-430 ferritic stainless steel used as solid oxide fuel cell interconnects

Ferritic stainless steels at high temperature and long operating time of solid oxide fuel cells (SOFC) face with some problems such as overgrowth and spallation of the surface oxide and cathode poisoning due to chromium evaporation. In the present work in order to improve the above-mentioned problems, the protective/conductive CuMn2O4 spinel coating was created on the AISI-430 ferritic stainless steel by means of pulse electrodeposition and subsequent heat treatment. Therefore, at first, the copper was applied to the substrate from a sulfate bath with an average current density of 48mA/cm2 and a deposition time of 4min. Subsequently, manganese was electrodeposited on the copper layer from a sulfate bath with an average current density of 125mA/cm2 and a deposition time of 8min. The frequency and duty cycle in the pulse electrodeposition of Cu and Mn Were considered100Hz and 80%, respectively. Then, to convert the metallic layers to spinel and also to evaluate its prevention of outward diffusion of Cr, oxidation was carried out at 750°C in the air for 24h and 100h. Microstructural evaluation of samples cross-section by scanning electron microscope (SEM) equipped with EDS indicated that the CuMn2O4 spinel layer acted as a barrier to outward diffusion of Cr effectively and the amount of Cr in the coating surface was zero. Also, coating layer had good adhesion to the substrate. By investigation of samples oxidation in the air for 0.5, 10 and 120min at 750°C, the results indicated that Mn was rapidly oxidized to MnO and Mn3O4, at the outset of the oxidation of the CuMn metallic coating. Gradually, the MnO and Mn3O4 disappeared and Mn2O3 was formed and the copper was oxidized to CuO. Finally, spinel phase of CuO and Mn2O3 was formed.

Electrodeposited Cu/buckypaper composites with high electrical conductivity and ampacity

Cu/buckypaper composites were prepared through electrodeposition of Cu onto buckypaper from a Cu sulfate electrolyte. The oxygen-containing functional groups were introduced to the surface of carbon nanotubes (CNTs) through acidification and oxidation. Incorporation of functional groups was shown to facilitate the spontaneous reduction of Cu ions on the surface of CNTs during immersion treatment. Under small deposition current density of 1 mA cm−2, Cu ions could penetrate into the reticulate structure of buckypaper and nucleate homogeneously on the CNTs, which led to the formation of a thicker transition layer. Functionalization also increased the nucleation rate of Cu on the CNTs. When the current density was 1 mA cm−2, the electrical conductivity of Cu/oxidized buckypaper composite reached the maximum value of 4.09 × 105 S cm−1 which was 76% of pure Cu. The ampacities of all the composites were obviously improved compared with electrodeposited pure Cu. The Cu/oxidized buckypaper composite had the maximum ampacity of 15437 A cm−2, which was 65% and 14% higher than that of pure Cu and Cu/original buckypaper composite, respectively. Good interface bonding and reticulate structure of CNTs formed in the transition layers are responsible for the relatively high electrical conductivities and high ampacities of Cu/buckypaper composites.

Dynamic Windows with Neutral Color, High Contrast, and Excellent Durability Using Reversible Metal Electrodeposition

Summary Dynamic windows, which switch between transparent and opaque states upon application of a voltage, have applications in buildings, automobiles, and switchable sunglasses. Here, we describe dynamic windows based on the reversible electrodeposition of Cu and a second metal on transparent indium tin oxide electrodes modified by Pt nanoparticles. Three-electrode cyclic voltammetry experiments reveal that the system possesses high Coulombic efficiency (99.9%), indicating that the metal electrodeposition and stripping processes are reversible. Two-electrode 25-cm 2 windows without bus bars uniformly switch between a transparent state (∼80% transmission) and a color-neutral opaque state (

Phase evolution during the electrodeposition of Cu–Sn–Zn metal precursor layers and its role on the Cu2S impurity phase formation in Cu2ZnSnS4 thin films

Abstract Metal precursor layers in the sequence of Cu(A)–Sn–Cu(B)–Zn (CTCZ) were electrodeposited on FTO–coated glass substrates to yield Cu2ZnSnS4, post sulphurization. Raman mapping and XRD analysis reveal the presence of Cu2S inclusions in the CZTS thin film obtained from the metal precursor in which the molar ratio of Cu(A)/Cu(B) is 0.33 (CTCZ–0.33). Such Cu2S inclusions are not present in the CZTS film obtained from the precursor with Cu(A)/Cu(B) molar ratio 3 (CTCZ–3). Systematic potentiodynamic and XRD studies of the component metal precursor layers reveals a significantly larger amount of unalloyed Sn in the CTCZ–0.33 metal precursor compared to that in the CTCZ–3 precursor. Sulphurization of the precursors thus results in a higher amount of SnS in the CTCZ–0.33 precursor. Subsequently, vaporization of SnS moves the overall composition of the sulphurized CTCZ–0.33 precursor outside of the CZTS formation window in the ternary phase diagram. This compositional shift leads to Cu2S + CZTS as the equilibrium phase assemblage for the film obtained from the CTCZ–0.33 precursor.

Microstructure and electrical conductivity of laminated Cu/CNT/Cu composites prepared by electrodeposition

Carbon nanotube (CNT) films were used as template for electrodeposition of Cu in different plating bath, and laminated Cu/CNT/Cu composites were prepared. The microstructure of all the laminated composites showed that Cu nucleus could insert into the pores of the CNT film, and formed an interfacial transition layer between the CNT film and the Cu coating. The electrodeposition behaviors of Cu on the CNT films in different plating baths were also analyzed. The results of electrical conductivity test showed that before annealing, the laminated composite prepared in basic acid plating bath has the highest electrical conductivity. After annealing at 900 °C for 2 h, the electrical conductivity of all specimens increased rapidly, and the electrical conductivity of the composite prepared in basic acid plating bath increased to 2.02 × 105 S cm−1. The annealing process was conductive to the diffusion and annihilation of voids within the interfacial transition layer, and the internal stress produced during the electroplating process could also be released through annealing. A simple and accurate quasi-classical model was proposed to calculate the resistance of the laminated composites. The measured resistances of the composites using four-point probe method were closer to that of the computed values, which indicated that the model used to describe the resistance of the laminated composite in the present study is feasible.

Electrodeposition behavior and characterization of copper–zinc alloy in deep eutectic solvent

Cu–Zn alloy films have been electrodeposited directly from their oxide precursors in choline chloride (ChCl)/urea-based deep eutectic solvent (DES). The reaction mechanism and the influence of the cathodic potential on the characteristics of the Cu–Zn alloy films are studied. Cyclic voltammetry and energy dispersive spectroscopy analyses reveal that the reduction of Cu(II) species relatively more preferentially occurs in comparison with the reduction of Zn(II) species, and Cu–Zn codeposition process can be controlled in the DES. Chronoamperometric investigation further confirms that the electrodeposition of Cu–Zn alloy on a Fe electrode follows the three-dimensional instantaneous nucleation-growth process. The micro/nanostructured Cu–Zn alloy films with different phase compositions can be facilely produced by controlling the cathodic potential. The obtained Cu–Zn alloy films typically exhibit enhanced corrosion resistances in 3 wt% NaCl aqueous solution. It is suggested that Cu–Zn alloy films can be sustainably electrodeposited from their abundant and inexpensive oxide precursors in DES. Micro/nanostructured Cu−Zn alloy films have been electrodeposited directly from CuO and ZnO precursors in deep eutectic solvent (DES), the electrochemical reaction mechanism and the nucleation-growth process of Cu−Zn alloy in the DES are investigated.

Influence of deposition potential on Cu2ZnSnS4 thin–film solar cells co–electrodeposited on fluorine–doped tin oxide substrates

Earth–abundant Cu2ZnSnS4 (CZTS) thin–film photovoltaic absorbers were synthesised by co–electrodeposition of Cu–Zn–Sn–S precursors on fluorine–doped tin oxide (FTO) coated glass substrates, followed by sulfurization in a sulfur atmosphere. In this paper, we investigated the effects of deposition potential on the properties of CZTS thin films and the photovoltaic performance of solar cells made with them. Initial increases in deposition potential increase the Zn content, decrease the Cu content, increase grain size, and improve the crystalline quality of the films. This boosts open circuit voltage (Voc) and short circuit current density (Jsc), thereby enhancing the efficiency of resulting solar cells from 0.56% to 4.73%. However, further increases in deposition potential cause rough surfaces, which reduces device performance by lowering Voc and increasing series resistance (Rs). This is the first study of CZTS thin–film solar cells made via co–electrodeposition on FTO–coated glass substrates at various deposition potentials. It provides a novel and promising method for fabricating high–efficiency CZTS bifacial thin–film solar cells.