Deposited Copper Oxide Research Articles

Homogeneous deposition of copper oxide on mesoporous 1D alumina nanofibres by combustion approach

Homogeneous deposition of copper oxide on mesoporous 1D alumina nanofibres by combustion approach

Direct Growth of Copper(II) Oxide (CuO) Nanostructures Films via One-Step Chemical Bath Deposition by pH Variation

An aqueous solution was prepared by mixing the copper(II) sulfate pentahydrate (CuSO4), lactic acid, sodium hydroxide (NaOH) and de-ionized (DI) water. Direct deposition of copper(II) oxide (CuO) nanostructures films on glass substrates was achieved by a simple, inexpensive and one-step chemical bath deposition method. The pH of the solution was varied at 11.7, 12.0, 12.3 and 12.6 and immersed at low temperature (90 °C). The influences of the pH solution towards the surface topography, morphology and thickness were investigated by a field emission scanning electron microscopy (FESEM), an atomic force microscope (AFM) and a surface profiler. Meanwhile, an X-ray diffractometer (XRD) was used to examine the structural properties of CuO films. The optical properties were measured by a UV-Vis spectroscopy. It was found that the grain size of the films decreases and the surface becomes smoother and more uniform by increasing the pH solution. The CuO nanostructures have high crystallinity with monoclinic structure which is preferentially grown along ( ) and (200) directions. Therefore, the film has great potential for gas sensor device.

Ion implantation induced phase transformation and enhanced crystallinity of as deposited copper oxide thin films by pulsed laser deposition

Copper oxide thin film of about 260–280nm thickness was deposited using pulsed laser deposition (PLD) on glass substrate at 350°C and post depositional sample treatment was performed by ion implantation with 50keV N5+ ion beam with varying particle fluence. Amorphous copper oxide thin film deposited at 80mTorr partial pressure of oxygen was transformed to cubic Cu2O phase (20.2nm) when implanted at 1×1016particles/cm2. While mixed Cu2O and CuO phases in the thin film deposited at 100mTorr oxygen pressure was transformed to single phase of Cu2O (23.5nm), with enhanced crystallinity when implanted with 2.5×1015particles/cm2. The phase transformation and improved crystallinity is attributed to thermal effect owing to stopping of incident ion beam. Implantation with higher particle fluence led to transformation to CuO phase with reduced crystallite sized and the increased electrical conductivity.

Electrodeposition and Characterization of Copper Oxide Thin Films for Solar cell Applications

Copper oxide thin films are being considered in thin film solar cells for its unique photovoltaic properties. Electrodeposition is one of the cheapest processes to deposit copper oxide thin films. In this study, copper oxide was electrodeposited on the copper substrate and gold plated glass substrate in an electrolyte bath containing 0.2M CuSO4.5H2O, 3M lactic acid and NaOH. A Potentiostat/Galvanostat with silver chloride electrode (Ag/AgCl) as a reference electrode was used for elctrodeposition. During deposition, the bath temperature and pH were maintained 600C and 12-12.5 respectively. Copper oxide was deposited at different potentials and deposition time. The films deposited at different electrodeposition conditions were characterized by Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS). The optical band gap was determined from the films deposited on gold plated glass substrate using Ultraviolet-Visible Spectroscopy. From visual inspection it was found that copper oxide film was black and adherent on copper substrate. In gold coated glass substrate copper oxide film was also black but bonding between the substrate and copper oxide film was not good. The SEM study reveal that the films become more compact and grain sizes of copper oxide films decreases at more negative potentials in deposition potential range. EDS analysis shows that percentage of oxygen in the copper oxide films increases with more negative potentials at the deposition potential range. It was found that with increase of time more adherent and uniform film thickness occurs. The variation of the thickness of copper oxide films with different deposition parameters was analyzed.

Simple method of deposition of CuO nanoparticles on a cellulose paper and its antibacterial activity

• Simple technique was used to deposit CuO nanoleaves on different substrates. • CuO deposited cellulose paper was investigated for disinfection properties. • The composite is suitable for point-of-use water treatment systems. We report a simple in situ technique to deposit nanoparticles of copper oxide on the cellulose paper which forms a stable layer of CuO. This method can be used to deposit copper oxide on any substrate provided that it is wettable and tolerates relatively high pH around 10–12 for several hours. Same method was applied to deposit CuO on commercial textile and polyethersulfone flat sheet. The resultant CuOpaper shows superior antibacterial activity against Gram-positive and Gram-negative bacteria. This antibacterial effect is due to release of copper ions from CuO nanoparticles on the paper. The resultant composite can be used as cheap point of use system to produce safe, pathogen free drinking water.

Growth and characterization of spray pyrolysis deposited copper oxide thin films: Influence of substrate and annealing temperatures

The effect of substrate and annealing temperatures on the structural, morphological, optical and electrical properties of spray deposited copper oxide thin films was investigated. The films were deposited on glass substrates using 0.05M of cupric acetate precursor at the substrate temperatures of 523, 623 and 723K. From the structural, morphological and optical characteristics, the film coated at 623K was found to have better crystallinity with mixed cuprite and tenorite phases. Thus, substrate temperature was fixed at 623K and films were prepared by increasing the molar concentration of cupric acetate to 0.1M. Further the effect of annealing on the various properties of the CuO films was investigated. The XRD patterns of the annealed films at 523, 623 and 723K for 6h revealed the formation of copper oxide thin films with tenorite phase.

Hydrophilic Cu2O nanostructured thin films prepared by facile spin coating method: Investigation of surface energy and roughness

We demonstrate a facile, uniform and large scale chemical route to synthesize the cuprous oxide (Cu2O) nanostructured thin film via spin coating technique. The samples were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), simultaneous thermal analysis (STA) and UV–visible spectra. Based on the results, the transparent Cu2O thin films were formed at the low temperature (275 °C) due to employed N2 atmosphere in annealing processes. The average roughness is decreased by increasing the number of layers from 11 to 6.4 nm for 1 and 5 times of successive deposition of copper oxide, respectively. Afterward, by increasing the cycle of deposition, the roughness increased (∼87%) owning to the transformation of the growth mechanism of thin films from Volmer–Weber to Stranski–Krastanov mode. Moreover, the prepared films were extremely hydrophilic with water contact angle about 45° and surface energy 54.26 mJ m−2 after 10-cycle coating. The smooth and low energy surface with this technique could be tailored for photoelectrochemical applications such as water splitting.

Effect of Substrate Bias in Copper Sputtering Plasma Measured by Langmuir Probe

There are several techniques to deposit the metal oxide thin film such as electron beam evaporator, pulse laser deposition and reactive magnetron sputtering deposition. In this experiment, magnetron sputtering deposition techniques will be used to produce a copper oxide thin film due to its simplicity and repeatability performance. Recently, copper oxide thin film has been studied because of its low cost material, sensitivity to ambient condition and easiness to produce oxide thin film. It is one of the p-type semiconductor oxides materials that are suitable to be used as a gas sensing material. In order to increase the sensitivity and to optimize the properties of copper oxide thin film, it is essential to study on the plasma properties during the deposition of copper oxide. In current studies, Langmuir probe was used to investigate the effect of substrate bias towards the fabrication of copper oxide thin film at rf dissipation power of 400 W. The oxygen flow rate was fixed at 8sccm. The Langmuir probe tip was focus at roughly 2 cm above the substrate holder. The ion and electron current were collected from the plasma environment. Then the electron temperature, electron density, ion density, ion flux, Debye length and plasma potential at various substrate biases were evaluated from the current-voltage curve. The electron temperature at various oxygen flow rates was almost unchanged. The effect of substrate bias toward the electron temperature was also almost unseen, except that the electron temperature at-40 V bias voltage was slightly lower than others. In addition, the ion flux at the same plasma condition shows that the ion flux was higher at-40 V substrate bias voltage. The results suggest that the ion bombardment effect toward the deposited copper oxide thin film would be higher at low oxygen flow rate. Thus it will create a rough surface morphology or nanostructured copper oxide thin film. This is a potential ways to improve the sensitivity of copper oxide gas sensor.

Fabricating and improving properties of copper matrix nanocomposites by electroless copper-coated MWCNTs

In this study, copper (Cu) nanocomposites reinforced by coated multiwall carbon nanotubes (MWCNTs) have been fabricated with different weight fractions of MWCNT. In the first step, the as-received MWCNTs were coated with Cu using electroless deposition process. In the next step, combination of sonication and ball milling (with two milling time of 1.5 and 3 h) was used for preparing MWCNT/Cu composite powders. Finally, the disk-shaped specimens were sintered by hot-press sintering machine. Characterization of sintered nanocomposites revealed that increasing milling time led to improved mechanical properties, but higher defect density on the MWCNT sidewalls is obtained which is especially undesirable for electrical properties of nanocomposite. Our results indicated that simultaneous improvements of interface reactions and distribution uniformity of MWCNTs and Cu are key factors for obtaining enhanced mechanical properties. Accordingly, enhancement of up to ~150 and ~86 % in microhardness compared to pure Cu and 1 wt% as-received MWCNT/Cu was achieved by addition of 1 wt% Cu-coated MWCNT. On the contrary, existence of oxygen atoms in the Cu and coated MWCNT interface (from functional groups and deposited copper oxide) obstructs considerable improvement of electrical resistivity compared to as-received MWCNT/Cu nanocomposites.

Temperature-controlled Deposition of Copper(I) Oxide and Metallic Copper Nanostructures from Single-source Molecular Precursor

A simple method of depositing morphology- and phase-tailored thin films of copper(i) oxide and metallic copper from [Cu(dmae)(TFA)]4·CH2Cl2 (1), where dmae is N,N-dimethylaminoethanolato and TFA is trifluoroacetato, on glass substrates by aerosol-assisted chemical vapour deposition is demonstrated. The tetrameric precursor 1 was synthesized and its structure was determined by single-crystal X-ray crystallography. Precursor 1 was applied for the deposition of nanostructured thin films of copper(i) oxide and copper nanowires at 250 and 375°C respectively. The deposited thin films were characterized by powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray diffraction, and ultraviolet–visible spectroscopy. The results indicate that the phase and morphology of the deposited material are strongly dependent on deposition temperature. UV-vis studies reveal that copper(i) oxide films with a band gap of 2.48 eV may find possible applications in tandem photoelectrochemical devices as light-absorbing material.

A glassy carbon electrode modified with poly(anthranilic acid), poly(diphenylamine sulfonate) and CuO nano-particles for the sensitive determination of hydrogen peroxide

We report on a modified glassy carbon electrode (GCE) for sensing hydrogen peroxide (H2O2). It was constructed by consecutive electrochemical deposition of poly(anthranilic acid) and poly(diphenylamine sulfonate) on the GCE, followed by the deposition of copper oxide (CuO). The morphology and electrochemistry of the modified electrode was characterized by atomic force microscopy, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. The catalytic performance of the sensor was studied with the use of differential pulse voltammetry under optimized conditions. This sensor displayed significantly better electrocatalytic activity for the reduction of H2O2 in comparison to a GCE without or with modification with CuO or polymer films alone. The response to H2O2 is linear in the range between 0.005 to ~11 mM, and the detection limit is 0.18 μM (at an S/N of 3).

Bipolar resistive switching properties of Ti-CuO/(hexafluoro-hexa-peri-hexabenzocoronene)-Cu hybrid interface device: Influence of electronic nature of organic layer

This study reports the change in the structural and junction properties of Ti-CuO-Cu structure on incorporation of a 2-dimensional (2D) organic layer comprising of n-type hexafluoro-hexa-peri-hexabenzocoronene (6F-HBC). A bipolar resistive switching is observed in the device having interface between sputter deposited copper oxide (CuO) and vacuum sublimated 6F-HBC hybrid interface. The CuO/6F-HBC hybrid interface exhibits rectifying I-V characteristics in complete contrast to the ohmic and rectifying characteristics of junctions based on individual 6F-HBC and CuO layers. Large change in resistive switching property from unipolar resistive switching in CuO/HBC to bipolar resistive switching in CuO/6F-HBC interface was observed. At the CuO/6F-HBC interface, C1s peak corresponding to fluorinated carbon is shifted by 0.68 eV towards higher binding energy (BE) side and O1s peak due to non-lattice oxygen is shifted by 0.6 eV towards lower BE, confirming the interaction of O2− ion in CuO with fluorinated carbon atoms in 6F-HBC at the hybrid interface. Correlation between conductive atomic force microscopy images and atomic force microscopy topography images, I-V characteristics in conducting, non-conducting, and pristine regions along with x-ray photoelectron spectroscopy results establishes the important role of hybrid interface to determining the resistive switching properties. This study demonstrates that the resistive switching and interface properties of a hybrid device based on inorganic and organic 2D materials can be modified by changing the electronic properties of organic layer by attaching suitable functional groups.

Effects of oxygen percentage on the growth of copper oxide thin films by reactive radio frequency sputtering

Copper oxide thin films were deposited onto glass substrates by reactive radio frequency magnetron sputtering at various oxygen percentage flow rates R(O2). X-ray diffraction analysis revealed that nanocrystallite copper oxide thin films with cubic, tetragonal, and monoclinic structure were formed at R(O2) values of 10%, 20%, and ≥30%, respectively. Energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy were used to verify the copper oxides phases. With increased R(O2), the root mean square surface roughness of the deposited films decreased from 4.82 nm to 1.78 nm. Moreover, both the band gap type and value changed with increased R(O2). For R(O2) at 20%, single phase tetragonal Cu4O3 thin film with a direct band gap of 2.20 eV was formed. For R(O2) ≥ 30%, single phase monoclinic CuO thin films with an indirect band gap of 1.20 eV–1.25 eV were formed. In addition, conductive copper oxide thin films tended to form for R(O2) < 30%, whereas insulator oxide thin films tended to form for R(O2) ≥ 30%. Through this study, the crystallization behavior, the band gap, and the resistivity properties of the deposited copper oxide thin films as a function of the R(O2) were obtained.

Atomic Layer Deposition of Copper Oxide using Copper(II) Acetylacetonate and Ozone

AbstractWe report on the deposition of copper oxide by atomic layer deposition (ALD) using copper acetylacetonate (Cu(acac)2) and ozone (O3) as precursors. The aim is to deposit oxides of copper as possible candidates for materials in all‐oxide photovoltaics. The present study results in ALD‐type deposition of the tenorite phase of copper(II) oxide in a temperature window of 150 °C to ca. 230 °C, with a growth rate of ∼0.038 nm per cycle. The resulting ALD characteristics, with a relatively large ALD window in deposition temperature, should be well suited for combination with additional deposition processes for the formation of complex compounds. The film thickness is studied using X‐ray reflectivity (XRR), and phase is determined by X‐ray diffraction (XRD). Surface roughness is studied using atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS) is used to investigate the chemical state of the deposited films.

Recovery of Ultrafine Copper Oxide Mineral with Vacuum Flotation

Tangdan copper oxide ore deposit, located in the northeast Yunnan province of China, is the largest independent copper oxide deposit in China. The ore from the deposit is characterized by low grade, high oxidation ratio and fine-grained dissemination, which results in the poor flotation recovery. The analysis of plant flotation data reveals that the loss of copper minerals into tailings is mainly with coarse size fraction, due to its insufficient liberation and finer size, especially for the size fraction below 10 microns, which are very difficult to be floated with conventional flotation methods. In order to improve the flotation performance of the ore, laboratory tests include Hallimond flotation and vacuum flotation were respectively conducted with pure malachite, the dominant copper oxide mineral in the deposit; and the results indicate that a finer grinding fineness up to -325 mesh even -400 mesh is required to decrease the copper loss in the coarse size fraction, and vacuum flotation provides a promising way for the recovery of ultrafine malachites.

Fabrication and Characterization of Coaxial p-Copper Oxide/n-ZnO Nanowire Photodiodes

The deposition of copper oxide onto vertically well-aligned n-ZnO nanowires by sputtering and the fabrication of p-copper oxide/n-ZnO coaxial nanowire photodiodes are reported. It was found that we could change the copper oxidation number to obtain Cu2O/ZnO nanowire photodiode, Cu4O3/ZnO nanowire photodiode and CuO/ZnO nanowire photodiode by simply changing the O flow rate during deposition. It was also found that noise equivalent powers were 6.1 × 10-11, 3.8 × 10-10, and 7.2 × 10-8 W while normalized detectivities were 6.35 × 109, 1.02 × 109, and 5.37 × 106 cmHz0.5 W-1 for the fabricated Cu2O/ZnO nanowire photodiode, Cu4O3 /ZnO nanowire photodiode and CuO/ZnO nanowire photodiode, respectively.

Deposition of copper oxide by reactive magnetron sputtering

Copper oxide films were deposited on silicon substrates by direct current magnetron sputtering of Cu in a mixture of O2 and Ar gases. Oxidation of the target as a result of adsorption or ion-plating of the reactive gases directly affects the discharge current and composition of the deposited films. We propose a kinetic model that relates the target oxidation to the discharge current, showing a one-to-one relationship between the discharge current characteristics and composition of the deposited films.

Fabrication of Heterojunctions Based on Chemically Deposited Copper Oxide Thin Films for Solar Cell Application

Fabrication of Heterojunctions Based on Chemically Deposited Copper Oxide Thin Films for Solar Cell Application

ALD-grown seed layers for electrochemical copper deposition integrated with different diffusion barrier systems

The deposition of Cu seed layers for electrochemical Cu deposition (ECD) via atomic layer deposition (ALD) of copper oxide and subsequent thermal reduction at temperatures between 110 and 120 °C was studied on different diffusion barrier systems. While optimization of the process is required on TaN with respect to reduction and plating, promising results were obtained on blanket PVD Ru. The plating results on layers of ALD Cu with underlying Ru even outperformed the ones achieved on PVD Cu seed layers with respect to morphology and resistivity. Applying the processes to via and line patterns gave similar results, suggesting that a combination of ALD Cu with PVD or ALD-grown Ru could significantly improve the ECD Cu growth.

Physical properties of copper oxide thin films prepared by dc reactive magnetron sputtering under different oxygen partial pressures

Abstract Nano-structured copper oxide thin films were deposited on glass substrates by dc reactive magnetron sputtering. The structural, morphological, electrical, and optical properties of the deposited copper oxide thin films were found to change with oxygen partial pressure. Changes in oxygen partial pressure during sputter deposition led to variations in Cu, Cu+ and Cu+2 concentrations, which resulted in corresponding changes in the electronic characteristics of sputtered semiconducting copper oxide films from initially n- to p-type and then from p-type back to n-type. These phenomena demonstrate that p-type copper oxide thin films can only be deposited by dc reactive magnetron sputtering within a narrow oxygen partial pressure range.