Zn Target Research Articles

Polyester fabric coated with Ag/ZnO composite film by magnetron sputtering

Ag/ZnO composite film was successfully deposited on polyester fabric by using direct current (DC) magnetron sputtering and radio frequency (RF) magnetron reaction sputtering techniques with pure silver (Ag) and zinc (Zn) targets. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to examine the deposited film on the fabric. It was found that the zinc film coated on Ag film before RF reactive sputtering could protect the silver film from oxidation. Anti-ultraviolet property and antistatic property of the coated samples using different magnetron sputtering methods were also investigated. The experimental results showed that Ag film was oxidized into in Ag2O film in high vacuum oxygen environment. The deposition of Zn film on the surface of the fabric coated with Ag film before RF reactive sputtering, could successfully obtained Ag/ZnO composite film, and also generated structural color on the polyester fabric.

Complex nanomineral formation utilizing kinetic control by PLAL

We used pulsed-laser ablation in liquids (PLAL) of Cu or Zn foil targets in water or in aqueous Cu or Zn salt solutions. PLAL in neat water generated mixtures of metal and (thermodynamically preferred) metal oxide nanomaterials, whereas the availability of select dissolved anions predictably led to the fabrication of more complex phase-pure nanominerals. PLAL of Cu foil in aqueous CuCl2 solution produced nano-paratacamite, Cu2Cl(OH)3, whereas nano-rouaite, Cu2(NO3)(OH)3, was formed in aqueous Cu(NO3)2 and NH4OH solution. Likewise, we synthesized simonkolleite, Zn5(OH)8Cl2·H2O, or layered zinc hydroxide nitrate, Zn5(OH)8(NO3)2·2H2O, nanoparticles by PLAL of Zn targets in aqueous ablation liquids with added ZnCl2 and NH4OH or Zn(NO3)2, respectively. Bimetallic zincian paratacamite resulted from PLAL of Cu foil in aqueous Cu and Zn chloride solution. Our results show that kinetic control exceeded thermodynamic product formation during nanosecond ultraviolet PLAL.

The continuous and discrete molecular orbital x-ray bands from Xe(q+) (12≤q≤29) +Zn collisions.

In this paper, the x-ray emissions are measured by the interaction of 1500–3500 keV Xeq+ (q = 12, 15, 17, 19, 21, 23, 26 and 29) ions with Zn target. When q < 29, we observe Ll, Lα, Lβ1, Lβ2 and Lγ characteristic x-rays from Xeq+ ions and a broad M-shell molecular orbital (MO) x-ray band from the transient quasi-molecular levels. It is found that their yields quickly increase with different rates as the incident energy increases. Besides, the widths of the broad MO x-ray bands are about 0.9–1.32 keV over the energy range studied and are proportional to v1/2 (v = projectile velocity). Most remarkably, when the projectile charge state is 29, the broad x-ray band separates into several narrow discrete spectra, which was never observed before in this field.

Effect of pre-annealing on the phase formation and efficiency of CZTS solar cell prepared by sulfurization of Zn/(Cu,Sn) precursor with H2S gas

The effect of pre-annealing on the phase formation behavior and efficiency of CZTS thin film solar cell prepared by sulfurization of sputtered Zn/(Cu,Sn) metal precursor with H2S gas was investigated. Precursor with stacking structure of Zn/(Cu,Sn) was deposited by sputtering of Cu, Zn, and Sn metal targets. The depth profile of metal elements and cell efficiency of the sulfurized CZTS films with H2S were observed to be critically dependent on the pre-annealing conditions. For the CZTS film prepared by sulfurization in N2-5vol.% H2S at 550°C after pre-annealing at 350°C in Ar, segregation of SnS phase at the surface region was observed to be pronounced. When the pre-annealing was performed at 350°C in N2-5vol.% H2S, however, uniform depth profile of metal elements with a small amount of CuS phase was observed. The CuS phase was disappeared with increase in the pre-annealing temperature in N2-5vol.% H2S. The phase formation behavior influenced by pre-annealing condition was observed to affect solar cell performance of the CZTS thin film synthesized at 550°C in N2-5vol.% H2S. In contrast to the CZTS thin film prepared with pre-annealing at 350°C in Ar showing bad efficiency (∼0.93%), the CZTS solar cells fabricated with pre-annealing at 450°C in H2S shows higher efficiency of 3.04%. By the optimization of Zn layer thickness, solar cell efficiency of 4.40% was obtained in the CZTS thin film prepared with pre-annealing at 450°C in N2-5vol.% H2S. This phenomenon was due to the change in the secondary phase formation behavior during sulfurization of the Zn/(Cu,Sn) metal precursor with various pre-annealing conditions.

Influence of absolute argon and oxygen flow values at a constant ratio on the growth of Zn/ZnO nanostructures obtained by DC reactive magnetron sputtering

In the present work we analyze the growth mechanism of Zn/ZnO nanostructured thin films obtained by DC reactive magnetron sputtering with variable absolute gas flow values. Zn target was sputtered at 80W DC power with variable absolute Ar:O2 flow values at a set ratio, in sccm: 3:0.3, 6:0.6, 8:0.8, 10:1, 15:1.5, 20:2 and 30:3. We obtained unique Zn/ZnO nanoflowers with morphology and properties changing as a function of gas flow values from dendritic/nanopetal structures for low flow to dense porous films for high flow. Zn core/ZnO shell composition results from surface oxidation of Zn crystallites to 4nm thick ZnO after exposure to atmospheric air that causes an increase in resistivity especially for denser, more porous films. Taking into account that the plasma properties measures using the Langmuir probe and optical emission spectroscopy remain constant as a function of gas flow values, we put forward that the structural evolution of films is influenced by oxygen incorporating into the film surface acting as an inhibitor − incorporating into the films and decreasing crystallite sizes and amorphizing the film structure.

Effect of sputter deposited Zn precursor film thickness and annealing time on the properties of Cu2ZnSnS4 thin films deposited by sequential reactive sputtering of metal targets

Cu2ZnSnS4 (CZTS) is made of earth abundant elements and also have suitable optical properties for solar cell applications. But, in phase diagram, CZTS exists in a narrow range of temperature and composition. Therefore, optimizing the elemental composition and annealing time is very important for obtaining phase pure CZTS. In this study, the effects of elemental composition and short annealing time on the structural and optical properties of reactively sputtered CZTS thin films are reported. Thin films were deposited by reactive sputtering of Cu: Sn (60:40wt%), Sn and Zn targets sequentially in the presence of H2S at room temperature. Amount of Zn precursor was varied by changing the sputter time for Zn. The films were rapidly annealed in inert atmosphere for varying time. The band gap of sample changed with change in the composition as well as annealing time. Sample with higher Zn content showed better crystallinity. With increase in the annealing time the crystallinity of samples improved. Sample annealed for 12min at 550°C was phase pure. Obtaining good quality film even for very short anneal time is the novelty of reactive sputtering method as all the elements are already mixed and short annealing is required only for crystal growth. Through detailed experiments, the optimum composition and annealing time required for the growth of phase pure CZTS has been established.

A study on structural formation and optical properties of Zn1-xCdxO thin films synthesized by the DC and RF reactive magnetron co-sputtering

The Zn1-xCdxO thin films were prepared on quartz by the direct current (DC) and radio frequency (RF) reactive magnetron co-sputtering technique with Zn and Cd metal targets. The influence of RF power on Cd target (PCd) on the structure and optical properties of Zn1-xCdxO films was investigated by using X-ray diffraction (XRD), transmission electron microscope (TEM), optical absorbance and photoluminescence (PL) measurements. The concentration and chemical states of Cd in films have been confirmed by energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) analysis. The results indicated that as the PCd varied from 0 to 120 W, all the Zn1-xCdxO thin films had a hexagonal wurtzite structure of pure ZnO and highly (002) preferred orientation, the Cd relative content in film is increased and the Zn relative content is decreased. Correspondingly, the optical band-gap of Zn1-xCdxO thin films with hexagonal wurtzite structure are tuned from 3.24 (PCd = 0) to 2.82 eV (PCd = 120 W). The location of the near-band-edge (NBE) emission peaks shift toward lower energy side from 388 to 440 nm, which is attributed to the decrease of band gap caused by Cd substitution.

Influence of Deposition Mode in Reactively Sputtered ZnO Underlayer on Thermal Stability of Thin Silver Films

The influence of deposition mode of the ZnO underlayer on the thermal stability of 20nm thick Ag films in the ZnO/Ag/SiN multilayer stacks were investigated. ZnO films were deposited by reactive sputtering of Zn target under different O2 flows corresponding to both transition and oxide modes. The films were characterized by sheet resistance, X-ray diffraction and SEM imaging before and after thermal annealing at 350°C, 400°C and 500°C, respectively. The results show that ZnO underlayer improves the thermal stability of the Ag films significantly. The ZnO deposition mode has huge impact on the Ag film on top of it. Compared with ZnO deposited in transition mode, ZnO deposited in oxide mode can induce more crystalline Ag film with stronger (111) preferred orientation, which is more thermally stable. For ZnO deposition in oxide mode, an optimal oxygen flow is identified to result in the most thermally stable Ag layer.

Nonlinear optical properties of the mixture of ZnO nanoparticles and graphene nanosheets

In this work, the experimental investigation of the nonlinear response of the mixture of ZnO nanoparticles and graphene nanosheets as a function of volumetric ratio of ZnO and graphene colloidal suspensions has been reported. The colloidal ZnO nanoparticle and graphene were synthesized by nanosecond pulsed laser ablation of Zn and graphite target in water, respectively. The X-ray diffraction pattern, transmission electron microscopy, Raman spectrum and linear absorption properties of ZnO nanoparticle and graphene nanosheets were used to characterize the ablation products. D band and G band of Raman shift at 1325 and 1580 cm−1, respectively, confirmed the formation of graphene nanosheets in water. Results show that the bandgap energy of mixtures decreased noticeably with increasing the amount of graphene in the suspensions. The nonlinear optical properties of the mixture of ZnO nanoparticles and graphene nanosheets were also investigated using open and close z-scan experiments. The positive nonlinear refractive index and absorption coefficient of the mixture of graphene nanosheets and ZnO nanoparticles were increased with increasing the concentration of graphene in the mixtures.

The electrical and thermoelectric properties of Zn-doped cuprous oxide

Zn-doped cuprous oxide thin films were deposited by direct current magnetron co-sputtering. Pure phase thin films can be obtained when the power of the Zn target is relatively lower than that of the copper target while increasing the power of the Zn target will lead to the presence of impurities such as Cu or ZnO. Zn-doped samples have smaller lattice constants, compared with undoped cuprous oxide. Zn-doped cuprous oxide thin films without impurities have larger optical band gaps and a relatively higher transmission in longer wavelength. All the cuprous oxide thin films, whether doped or undoped, are p-type, as revealed by Hall effect measurements and the positive Seebeck coefficients. Zn-doped cuprous oxide thin films have a lower conductivity due to compensation than undoped Cu2O thin films. The Seebeck coefficient of all samples was found to decrease with the increase in the measurement temperature. Zn-doping does not have an obvious effect on the Seebeck coefficient. At temperatures slightly higher than room temperature, Zn-doped cuprous oxide thin films have relatively smaller power factors than undoped samples.

Production of projectile and target K-vacancy in near-symmetric collisions of 60–100 MeV Cu9+ ions with thin Zn target**Project supported by the Joint Funds of the National Natural Science Foundation of China (Grant No. U1332122).

We report studies on both target and projectile K-shell ionization by collisions of Cu9+ ions on the thin Zn target in the energy range of 60–100 MeV. In this work, the relative ratio for the production of the target to projectile K-vacancy is measured. The result shows that it almost remains stable over this energy range and has good consistency with the predictions by vacancy transfer via the 2pσ–1sσ rotational coupling, which gives experimental evidence for K-vacancy sharing between two partners. Furthermore, the discussion for comparisons between the experimental ionization cross sections and the possible theoretical estimations is presented. These comparisons suggest that the experimental data agree well with those predicted by the Binary–Encounter approximation (BEA) model but are not in good agreement with the modified BEA calculations. It allows us to infer that the direct ionization (and/or excitation) is of importance to initial K-vacancy production before 2pσ–1sσ transitions in the present collision condition.

Effects of coupling to breakup channels in reactions induced by weakly bound and halo nuclei

The experimental elastic scattering angular distributions of the collisions involving the weakly bound nuclei 6,7 Li and the halo nucleus 6 He on the same 64 Zn target at several energies around the Coulomb barrier were measured at the Laboratori Nazionali del Sud (LNS, Italy), and the Cyclotron Research Center, Louvain La Neuve (Belgium), respectively. The experimental elastic scattering angular distributions of the 6,7 Li + 64 Zn systems have been analyzed within the continuumdiscretized coupled-channels method, while the 6 He + 64 Zn data have been compared with both continuum-discretized coupled-channels and coupled-reaction-channels calculations.

Structural and optical properties of Zn-doped SnO2 films prepared by DC and RF magnetron co-sputtering

In the present work, the Zn-doped SnO2 (SnO2:Zn) thin films, with different Zn-doping concentration, were successfully prepared on Si (100) and glass substrates by direct current (DC) and radio frequency (RF) magnetron co-sputtering. The effects of dopant concentration, determined by the sputtering power applied on Zn target, on the structural, photoluminescent and optical performances of Zn-doped SnO2 films were investigated by X-ray diffraction(XRD), scanning electron microscope(SEM), energy dispersive X-ray (EDX),high-resolution transmission electron microscopy(HRTEM) and Ultraviolet–Visible-Near IR spectroscopy. The results show all these films exhibited excellent crystalline quality with tetragonal rutile structure. Two photoluminescence (PL) peaks related to Zn-doping were detected at about 351 nm (3.53 eV) and 369 nm (3.36 eV). Moreover, the average transmittance and the band gap energy of the films continuously decreased from 85% to 75% and from 3.52 eV to 3.34 eV, respectively, with the increase of the doping level. The excellent properties of Zn-doped SnO2 films make them capable for wider applications.

Spatially resolved electron density and electron energy distribution function in Ar magnetron plasmas used for sputter-deposition of ZnO-based thin films

Langmuir probe and trace rare gases optical emission spectroscopy were used to analyze the spatial structure of the electron density and electron energy distribution function (EEDF) in a cylindrical Ar magnetron plasma reactor used for sputter-deposition of ZnO-based thin films. While a typical Bessel (zero order) diffusion profile was observed along the radial direction for the number density of charged particles at 21 cm from the ZnO target, a significant rise of these populations with respect to the Bessel function was seen in the center of the reactor at 4 cm from the magnetron surface. As for the EEDF, it was found to transform from a more or less Maxwellian far from the target to a two-temperature Maxwellian with a depletion of high-energy electrons where magnetic field confinement effects become important. No significant change in the behavior of the electron density and EEDF across a wide range of pressures (5–100 mTorr) and self-bias voltages (115–300 V) was observed during magnetron sputtering of Zn, ZnO, and In2O3 targets. This indicates that sputtering of Zn, In, and O atoms do not play a very significant role on the electron particle balance and electron heating dynamics, at least over the range of experimental conditions investigated.

Tuning the band gap and nitrogen content of ZnOxNy thin films deposited by reactive HiPIMS

We show that it is possible to manipulate the stoichiometry and composition of the thin films deposited by reactive high power impulse magnetron sputtering (HiPIMS) by the design of the discharge pulsing scheme. This is illustrated for the case of the short-pulse HiPIMS of a pure Zn target in Ar/N2/O2 mixture gas (low content of O2), where the variation of the discharge pulsing frequency has led to depositions of crystalline ZnOxNy thin films with the nitrogen content and optical band gap values ranging from 0 to 6.2at.% and from 3.34 to 1.67eV, respectively. The fine control of nitrogen content in the deposited ZnOxNy thin films was obtained by the use of smooth transitions of the reactive HiPIMS discharge between the compound and metallic target sputtering modes. Thus, the yield of the sputtered metal atoms was controlled by the discharge pulsing frequency from low values, in the compound target sputtering mode, to large values, in the metallic target sputtering mode. The controlled amount of metal atoms in the gas phase and the limited amount of oxygen in the deposition chamber determined depositions of films with variable content of nitrogen.

Comparison of Cu2ZnSnS4 thin films and solar cell performance using Zn target with ZnS target

Cu2ZnSnS4 (CZTS) thin films are considered as ideal absorption materials for next generation thin film solar cells due to their excellent optical and electrical properties as well as low cost. Two types of CZTS thin films were prepared via sputtering with Zn or ZnS targets (Cu/SnS/Zn and Cu/SnS/ZnS). After sulfurization, the microstructure and distribution of the elements and the electrical properties of the thin films obtained using the Zn and ZnS targets were compared. The CZTS thin films obtained from the Zn target exhibit a large grain, smooth surface and less ZnS accumulation between the CZTS and Mo, resulting in improved junction characteristics and electrical properties. The CZTS solar cells that were fabricated with the Zn target exhibit an improved conversion efficiency of 5.06% relative to that of CZTS solar cells using the ZnS target.

Defects in ZnO nanoparticles laser-ablated in water–ethanol mixtures at different pressures

The effect of liquid medium and its pressure on the photoluminescence of ZnO nanoparticles prepared via laser ablation of Zn targets in various water–ethanol mixtures is studied. As the ethanol content increases, the photoluminescence of the product changes, while metallic zinc is observed to emerge in nanomaterials prepared in ethanol-rich environments. The applied pressure had a less profound effect, mainly affecting materials produced in water or water–ethanol, and much less those generated in pressurized ethanol. Tuning the reactivity of the liquid and pressurizing it during laser ablation is demonstrated to be promising for tailoring the emission properties of the product.

Structural, electrical and magnetic characterization of in-situ crystallized ZnO:Co thin films synthesized by reactive magnetron sputtering

Zn1−xCoxO (0 < x < 0.146) conductive thin films have been deposited by reactive magnetron sputtering of metallic Zn and Co targets at high pressure and temperature. The structural properties have been investigated by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It has been observed that all as-deposited films are crystallized in pure hcp ZnO structure and neither traces of metallic nor oxide Co-rich clusters were detected. The average grain size estimated from full width at half maximum of XRD results varied between 65 and 83 nm. XPS analyses exhibit that Co ions are successfully entered into ZnO lattice as Co+2. The electrical properties including conductivity, carrier density and carrier mobility were determined by Hall effect measurements in a temperature range from 300 K to 475 K. The conductivity of the films decreases from σ300K = 2.2 × 104 to 2.3 × 10−1 Sm−1 as the Co content changes from 0 to 0.146. Magnetic measurements reveal the absence of ferromagnetism even at 3 K and a paramagnetic Curie–Weiss behavior associated to magnetic clusters.

Simultaneous imaging of Zn(2+) and Cu(2+) in living cells based on DNAzyme modified gold nanoparticle.

Trace Zn(2+) and Cu(2+) in living cells play important roles in the regulation of biological function. It is significant to simultaneously detect the cellular Zn(2+) and Cu(2+). Here, we present a novel two-color fluorescence nanoprobe based on the DNAzymes for simultaneous imaging of Zn(2+) and Cu(2+) in living cells. The probe consists of a 13 nm gold nanoparticle, DNAzymes that are specific for Zn(2+) and Cu(2+), and the substrate strands labeled with fluorophores at the 5' end and quenchers at the 3' end. The fluorescence of the fluoreophores is quenched both by the gold nanoparticle and the quencher. After the nanoprobes are transferred into the cells, the substrate strands would be cleaved in the presence of the Zn(2+) and Cu(2+) target, resulting in disassociation of the shorter DNA fragments containing fluorophores, which produce fluorescence signals correlated with the location and concentration of the Zn(2+) and Cu(2+). The nanoprobe exhibits high specificity, nuclease stability, and good biocompatibility. Moreover, the nanoprobe can simultaneously monitor the cellular Zn(2+) and Cu(2+) with an on-site manner, providing the information on localization and concentration of targets, which is significant to further research the Zn(2+)- and Cu(2+)-relative cellular events and biological process. The proposed method has shown great potential in the detection of multiple metal ions in living cells, which may help us to better understand the function of metal ions in the fields of biochemistry, molecular biology, and cellular toxicology.

Synthesis of Cu2ZnGeS4 thin film via sulfurization of RF magnetron sputtered precursor

Quaternary Cu2ZnGeS4 thin film was synthesized by sulfurization of radio-frequency magnetron sputtered precursor at a high temperature for the first time. The precursor was deposited sequentially on a glass substrate by the sputtering method from high purity Cu, Zn and Ge elemental targets with the stacking order: Ge/Zn/Cu/glass. Energy dispersive X-ray mapping results demonstrate that the Cu, Zn, Ge and S elements are uniformly distributed in Cu2ZnGeS4 thin film. The surface micrograph shows a compact and densely packed morphology. The X-ray diffraction results and Raman spectroscopy analysis indicate that the as-prepared thin film has pure phase. It can be confirmed that the microstrain and crystal disorder exist in the thin film by Williamson–Hall analysis method. The absorption spectrum demonstrates that the value of the band gap for Cu2ZnGeS4 thin film is 1.85 eV. These results indicate that sulfurization of magnetron sputtered precursor is a suitable process for the growth of Cu2ZnGeS4 thin film.