氧化镍用磁控溅射制备的方法

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Nickel oxide is a promising material for transparent electronics applications. This semiconductor demonstrates the possibility of modifying its physical properties depending on the method of growth and subsequent processing. Here the effects of the discharge power are reported during reactive dc magnetron sputtering, as well as the modes of subsequent annealing of NiO films, on their structural, electrical, and optical properties. NiO films are annealed at various temperatures both in an oxygen‐containing environment and under vacuum conditions. Deposited NiO films have a polycrystalline structure with a preferred orientation (200) for the low discharge power mode and (111) for the high discharge power mode. However, obtained NiO films exhibit crystallinity improvement after annealing. The presence of both Ni2+ and Ni3+ oxidation states in the deposited films is found. In addition, it is shown that the relative carrier concentration (Ni3+/Ni2+ peak area ratio) can be controlled by choosing the NiO film preparation mode. The trend in this ratio corresponds to the trend in film conductivity and the number of free‐charge carriers. The deposited films are semitransparent, and the estimated optical bandgap of NiO is in the range from 3.50 to 3.74 eV.

Herein, Li‐doped NiO thin films are deposited on glass substrates using pressure‐gradient radiofrequency magnetron sputtering, with Ar and O2 as sputtering gases. Following film fabrication, their crystal structures, optical features, and electrical properties are investigated as functions of O2 flow rate to the total flow rate (O2/(O2 + Ar)) of 10 sccm. The deposited films are also annealed at 600 °C for 1 h in an oxygen atmosphere. Notably, the resistivity of the as‐deposited films decreases significantly by three orders of magnitude from 106 to 0.0232 Ω cm when the sputtering gas is changed from pure Ar to pure O2. However, the transmittance decreases with increasing oxygen flow rate. Investigations on the temperature dependence of conductivity reveal hole conduction in the range of ≈320–420 K owing to small polaron hopping.

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Ultraviolet photodetector with p-n heterojunction is fabricated by magnetron sputtering deposition of n-type indium gallium zinc oxide (n-IGZO) and p-type nickel oxide (p-NiO) thin films on ITO glass. The performance of the photodetector is largely affected by the conductivity of the p-NiO thin film, which can be controlled by varying the oxygen partial pressure during the deposition of the p-NiO thin film. A highly spectrum-selective ultraviolet photodetector has been achieved with the p-NiO layer with a high conductivity. The results can be explained in terms of the "optically-filtering" function of the NiO layer.

Nickel oxide (NiO) thin films were deposited by an RF magnetron sputtering process in different atmospheres: one with a mixture of nitrogen and argon, and another with oxygen and argon. The structural, optical and electrical properties of NiO films were investigated using the spectroscopy, atomic-force microscopy and resistivity measurements. The dependencies of the film properties on atmosphere composition were studied. Optimization of the NiO thin film properties was carried out for further fabrication of effective hole transport layers for perovskite solar cells.

Metal oxides, due to their wide band gap, are well suited for use in photodetectors as the active light-absorbing layer. While there have been extensive studies on n-type oxides, such as tungsten oxide and zinc oxide, there is relatively little work on the use of p-type oxides, such as nickel oxide (NiO), for photodetectors. Using these p-type oxides along with n-type conducting oxides to form heterojunctions can improve the detection capabilities by efficient separation of charge carriers. In this work, the photoresponse of a p-type NiO thin film, grown by room temperature reactive magnetron sputtering from a pure nickel target onto a conducting n-type indium-doped tin oxide (ITO) substrate, is investigated. Different ratios of oxygen to argon (10/45, 15/45, and 20/45) during sputtering are investigated, and the effect of oxygen concentration on the optical properties of the NiO film is studied, which helps in modulating the photoresponse of the developed detector. The O2/Ar ratio, with a value of 15/45, is found to perform better among the three ratios. For the corresponding photodetector, the current under illumination, is found to be nearly three orders of magnitude higher than the dark current, even at a very low applied voltage of 0.1 V. The calculated responsivity (at 0.012 A/W) is found to be the best among all three values. The device also has an excellent transient current response with a rise time of 0.5 s and a decay time of 1.4 s, which is the fastest transient behavior among all three ratio-based devices. The work paves the way for using metal oxide-based heterojunctions as wide band gap photodetectors. Nickel oxide films grown by reactive magnetron sputtering A wide band gap heterostructure-based photodetector is fabricated using nickel oxide Effect of oxygen gas on the photodetector properties is evaluated Nickel oxide films grown by reactive magnetron sputtering A wide band gap heterostructure-based photodetector is fabricated using nickel oxide Effect of oxygen gas on the photodetector properties is evaluated

Nickel oxide NiO thin films have been synthesized by RF magnetron sputtering with accompanying ion-beam treatment. The films were synthesized on glass substrates at three different partial pressures (4, 6 and 7 %) of oxygen in the working chamber. Depending on the current density of the ion beam used for the treatment and the oxygen pressure, the thickness of the films ranged from 100 to 800 nm. A significant influence of the ion beam current density on the parameter characterizing the average crystallite size of NiO, as well as on the parameters of its crystal lattice, was shown by X-ray diffractometry. An absorption band near the wavelength of 232 nm was detected in the optical reflectance spectra of the films measured in the range of 190-1100 nm. Using z-scanning method with a nanosecond laser at a wavelength of 532 nm it is shown that the synthesized films exhibit nonlinear absorption due to two-photon absorption. It is demonstrated that there is an optimal current density of ion-beam irradiation at which the nonlinear absorption coefficient of the films reaches the maximum value and their resistivity reaches the minimum value.

NiO thin films with varied oxygen contents are grown on Si(100) and c-Al2O3 at a substrate temperature of 300 °C using pulsed dc reactive magnetron sputtering. We characterize the structure and optical properties of NiO changes as functions of the oxygen content. NiO with the cubic structure, single phase, and predominant orientation along (111) is found on both substrates. X-ray diffraction and pole figure analysis further show that NiO on the Si(100) substrate exhibits fiber-textured growth, while twin domain epitaxy was achieved on c-Al2O3, with NiO(111)∥Al2O3(0001) and NiO[11¯0]∥Al2O3[101¯0] or NiO[1¯10]∥Al2O3[21¯1¯0] epitaxial relationship. The oxygen content in NiO films did not have a significant effect on the refractive index, extinction coefficient, and absorption coefficient. This suggests that the optical properties of NiO films remained unaffected by changes in the oxygen content.

This study aims to synthesize Nio film doped with Sn element at a ratio (2,4,8 and 16) % by using Physical Vapour Deposition RF Sputtering with annealing at 200, 300, 400, and 500. The results of XRD appear to be crystallizing of the thin film preparation at 500 ºC, and the annealing under this temperature will be amorphous. The SEM and AFM tests of structures, roughness, and particle size found that the particle size will be decreased and surfaces will be smoother with an increase in temperature of annealing at 500 ºC. The roughness value is (22-84) nm, and the lower values of roughness are at 500 ºC. Transmittance decreases with Sn dopant concentration, its minimum occurs for 16% SNO (sample: 3.32 eV), and by increasing more Sn dopant, it gets wider optical band gap. The resistivity decreases by increasing the tin dopant. Annealing drastically lowered the band gap, as we saw in some samples, it ran below, not annealed thin films.

Sputtered nickel oxide (NiOX) is a promising material for hole transport layers (HTLs) in industrializing perovskite solar cells (PSCs) due to its scalable and conformal growth. However, its low conductivity and interfacial instability limit device performance. Herein, high-quality undoped NiOX (DC-N) HTLs are developed fabricated via direct current (DC) reactive sputtering (Ni target) coupled with low-temperature (≤ 200 °C) air annealing. By synergistically modulating process conditions, nickel vacancy density is tailoreded to balance photoelectric properties and interfacial stability of DC-N HTLs, while elucidating trade-offs among conductivity, transmittance, and interfacial stability. Contrastive analysis reveals that the DC-N HTLs outperform conventional RF-sputtered NiOX HTLs (derived from ceramic targets, doped or undoped), mainly attributed to their outstanding conductivity, an ideal Ni3+/Ni2+ ratio, good crystallization, and excellent interface properties, which mitigate parasitic absorption, recombination losses, and charge transport losses. By employing DC-N HTLs, inverted PSCs with a 1.68 eV bandgap achieve a power conversion efficiency (PCE) of 20.71%, increasing to 22.45% with Me-4PACz/Al2O3 interlayers and thick-film perovskite. Notably, integrating DC-N HTLs into textured perovskite/silicon tandem solar cells delivered a PCE of 32.02% (1.0 cm2 aperture area), providing valuable insights for NiOX-based tandem photovoltaics.

This paper presents a study on the development and optimisation of thin films of nickel-vanadium oxide (NiVxOy) deposited by DC reactive magnetron sputtering (RMS) controlled by P.E.M. (plasma emission monitoring). The hysteresis behaviour of the Ni emission signal as a function of oxygen incorporation was analysed using optical emission spectroscopy (OES), enabling the identification of critical working points along the hysteresis loop and their correlation with film growth mechanisms. Compared to the non-monotonic nature of the target discharge voltage signal, OES provided a simplified response for real-time process control. A set of coatings was deposited under various working pressures (0.6 and 2.0 Pa) and plasma emission monitoring (P.E.M.) conditions and was thoroughly characterised in terms of microstructure, composition, optical modulation, and electrochemical performance. Films deposited at high pressure and under 30% P.E.M. conditions showed an optimal balance between optical modulation (21%) and charge density (4 mC/cm2), which was attributed to the increased Ni3+ content and the surface cracks at low density.

Nickel oxide (NiO) nanostructure was successfully prepared via reactive DC magnetron sputtering on the soda-lima glass substrate, which can be used for various applications. Xray diffraction (XRD) investigations were used to evaluate NiO with two annealing durations. The results revealed that the deposited films had a cubic structure and polycrystalline nanoparticles. A significant polycrystalline structure could be seen in the sputtered films as a diffraction peak oriented toward NiO (200). Field-emission Scanning Electron Microscopy (FE-SEM) analysis identified the surface morphology of NiO nanoparticles prepared at two different annealing times with the two average sizes (24 and 32 nm) respectively. The samples' roughness was assessed using atomic force microscopy (AFM). Increased annealing time was shown to result in a decrease in grain size. The energy band gap (Eg) expanded with increasing annealing time, according to UV-visible spectroscopy (UV-Vis). FTIR spectroscopy was used to determine the functional groups of NiO nanoparticles and their bonding nature. The results indicate that optical characterizations are more sensitive to the annealing period.

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Fractal and multifractal are the most important processes and concepts in describing and examining surface morphology, and for this reason, these concepts are an important approach for analyzing the properties and surface geometry of thin films. In this article, multifractal analysis was performed on images, prepared using atomic force microscopy (AFM), of the surface morphology of nickel oxide thin films deposited by RF‐Magnetron sputtering at different thicknesses on the glass substrate. The effect of thickness on the surface properties of the layers was studied by applying multifractal and statistical methods on AFM images. The results obtained from the multifractal spectrum show that the surface of the nickel oxide thin films deposited at different thicknesses are multifractal. The multifractal analysis demonstrated that multifractality and complexity of the surface of nickel oxide thin films changes and decrease with thicknesses. We also used statistical parameters to better examine AFM images to study the effects of layers thickness on the deposited NiO thin films. The results indicated that the statistical parameters are a function of the layer's thickness of NiO thin films. Hence, the isotropic properties and functional parameters changed with changing surface thickness.

The performance of NiO-based supercapacitor electrodes for energy storage systems was enhanced by doping Cu into NiO thin films (200 nm) using radio-frequency magnetron co-sputtering on 3D porous Ni foam substrates, followed by rapid thermal annealing. The Hall effect measurements demonstrated enhanced electrical conductivity, with resistivity values of 1.244 × 10−4 Ω·cm. The 3D porous NiO:Cu electrodes significantly increased the specific capacitance and achieved a value of 1809.2 Fg−1, with the NiO:Cu (10 at% Cu) thin films at a scan rate of 5 mVs−1, which is a 2.67-fold increase compared with the undoped NiO films on a glass substrate. The 3D porous NiO:Cu electrodes significantly improved the electrochemical properties of the NiO-based electrode, which resulted in a higher specific capacitance for enhancing the energy storage performance during grid stabilization.

NiO-based hole-transport layers are crucial for high-efficiency perovskite solar cells. An industrial deposition method of NiO films is magnetron sputtering using ceramic targets. NiO targets doped with Li contents at 1%, 3%, and 5% were designed, and the doping contents and sintering temperatures were investigated. All the targets have a face-centered cubic phase, dense microstructure, and an average size of a few microns. The NLO targets sintered at an optimal temperature of 1400 °C exhibited high relative density (>98%) and low resistivity (<6 Ω∙cm). These results pave the way for depositing NiO-based hole-transport layer by magnetron sputtering.

Doping engineering has been applied in niobium-doped NiO (NiO:Nb) by adding nitrogen (N) in its structure. The rf-sputtered films were made from a Ni-Nb composite target on unheated substrates at 300 W rf power and 5 mTorr total pressure. The plasma contained 50% Ar and 50% O2 for the fabrication of the single-doped NiO:Nb film (AΝ film), and N2 gas for the incorporation of N in the Ni-O-Nb structure. The N2 in plasma was introduced by keeping constant the flow rates of O2 and N2 gasses (O2/N2 = 1) and reducing the amount of Ar gas, namely 94% Ar, 3% O2, and 3% N2 (film AN1); 50% Ar, 25% O2, and 25% N2 (film AN2); and 6% Ar, 47% O2, and 47% N2 (film AN3). All films had the single phase of cubic NiO and both Nb and N in the Ni-O structure were revealed by XPS experiments. The roughness of the films was increased with the increase in N in plasma. Post-deposition thermal treatment improved the crystallinity and reduced the structural disorder of the films. The AN2 film was found to be the most transparent of all films, exhibiting the widest band gap, 3.72 eV, and the narrowest Urbach tail states’ width, 313 meV. The AN and the AN2 films were employed to form NiO/TiO2 heterostructures. The NiO:Nb/TiO2 and NiO:(Nb,N)/TiO2 heterostructures exhibited a visible transmittance of around 42% and 75%, respectively, and both showed rectification properties. Upon illumination with UV light, the NiO:(Nb,N)/TiO2 diode exhibited enhanced photovoltaic performance when compared to the NiO:Nb/TiO2 solar cell: the short-circuit current densities were 0.2 mA/cm2 versus 1.4 μA/cm2 and the open-circuit voltages were 0.5 V versus 0.2 V. The output characteristics of the p-NiO:(Nb,N)/n-TiO2 UV photovoltaics can be further improved by proper engineering of the individual layers and device processing procedures.

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Since transparent conductive oxides (TCOs) provide electrical conductivity together with optical transparency, they have found wide applications in optoelectronic devices and photovoltaics. Among the TCOs, nickel oxide (NiO) is challenging due to its inherent trade-off between transparency and electrical conductivity. To address this challenge, one effective approach is to deposit a metal layer onto NiO thin films. In this work, NiO, NiO/Au, NiO/Ag, and NiO/Cu thin films are prepared by sputtering and thermal evaporation techniques on glass substrates and fully characterized finding the proper film for optoelectronic applications. The electrical and optical properties of the fabricated films are examined by four-point probe measurements and optical spectrometry. According to the obtained results, the NiO/Au, NiO/Ag, and NiO/Cu bilayers show sheet resistance of 200, 338, and 925 Ω sq−1 respectively while their optical bandgaps vary from 3.2 to 3.76 eV. These findings provide valuable insights into the performance of these films, making them potentially viable choices for various optoelectronic applications.

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In this work, NiO thin films were deposited on glass and n-type Si at different substrate temperatures utilizing reactive RF-sputtering technique. The influence of substrate heating on the crystal structure, surface morphology, and optical and electrical properties of NiO thin films was studied using x-ray diffraction, scanning electron microscopy, UV-vis transmission spectroscopy, and Hall effect measurements. The x-ray diffraction data revealed a significant improvement in crystallinity, with the NiO films preferentially growing along the (111) direction as the substrate temperature increased. The scanning electron microscope images indicated the more explicit grain boundaries above 250 °C. The average light transmittance of the NiO thin film exhibited a significant improvement from 31% to 72% in the visible range. In addition, the optical bandgap was found to increase from 3.19 to 3.51 eV as the substrate temperature increased. The NiO films presented high carrier concentrations ranging from 1.044 × 1019 to 2.847 × 1019 cm−3 and a low surface resistivity of 0.260 Ω.cm. The optimal characteristic parameters of the p-NiO/n-Si diodes (VOC = 0.702 V, n = 4.998, and ΦB = 0.761 eV) were recognized at a substrate temperature of 250 °C. The results demonstrate that sputtered NiO thin films are highly applicable for ultraviolet optoelectronic devices.

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Herein, the recent findings on hollow cathode gas flow sputtering (GFS) of transparent conductive oxides (TCO) films are reviewed. The GFS is a unique deposition technique that offers extraordinary process conditions for thin‐film growth. The GFS core element is a hollow cathode discharge operating in the mbar pressure range. The sputtered atoms are transported by means of forced convection. These key features allow for unique deposition conditions: i) GFS is a remote process where reactive gas does not interact with the sputtered target surface. This allows for high process stability at any reactive gas partial pressure, opening up even the pathway for combined physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD) synthesis. ii) The GFS plasma delivers high plasma density in the order of 1012 cm−3 at the substrate position. When bipolar pulsing is applied to the hollow cathode, plasma‐activated growth can be obtained even for insulating substrates. iii) Doped films can be produced in an elegant way when the target is composed from ring segments to adjust the specified doping level. In this article, the focus is on the process development using direct simulation Monte Carlo modeling of the deposition process and on the optimization of bipolar pulsing. Follow on this, two application cases are introduced: i) synthesis of p‐type NiOx and Cu‐doped and NiOx‐doped films for application as hole conductor in perovskite solar cells where improved device stability is achieved compared to surface assembled monolayers which are state of the art and ii) synthesis of ZnOxNy films with the perspective for usage as semiconductive films in thin‐film transistors.