[en] In this paper, N-doped diamond-like carbon (DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition (HWP-CVD) with the Ar/CH₄/N₂ mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), Raman spectra, and atomic force microscopy (AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min⁻¹, which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C−C sp³ bond content increases firstly up to the maximum (20%) at 10 sccm of N₂ flow rate, and then decreases with further increase in the N₂ flow rate. The maximum Young’s modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N₂ flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010. (paper)

[en] Al-doped zinc oxide (AZO) films are prepared by dual ion-beam assisted sputter deposition at room temperature. An assisting argon ion beam (ion energy E_i = 0–300 eV) directly bombards the substrate surface to modify the properties of the AZO films. The effects of assisting ion beam energy on the characteristics of AZO films were investigated based on transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and photoluminescence measurement. With increasing assisting ion beam bombardment, the crystalline quality of the AZO films was improved and the oxygen vacancies were increased observably. Two red emissions originating from the oxygen vacancies in the films appear at 1.71 and 1.64 eV. This study suggests that wide-band-gap materials could act as effective visible light emitters and ion beam bombardment provides a simple route to synthesize such materials. - Highlights: ► Al-doped ZnO (AZO) thin films were prepared by dual ion-beam sputter deposition. ► By assisting-ion beam bombardment, AZO films have a better c-axis orientation. ► The crystalline quality of AZO films was improved by assisting-ion beam bombardment. ► Two red emissions originate from the oxygen vacancies in the films.

[en] Here, the high magnetic field helicon experiment system is a helicon wave plasma (HWP) source device in a high axial magnetic field (B₀) developed for plasma–wall interactions studies for fusion reactors. This HWP was realized at low pressure (5 × 10^–3 – 10 Pa) and a RF (radio frequency, 13.56 MHz) power (maximum power of 2 kW) using an internal right helical antenna (5 cm in diameter by 18 cm long) with a maximum B 0 of 6300 G. Ar HWP with electron density ~10¹⁸–10²⁰ m^–3 and electron temperature ~4–7 eV was produced at high B₀ of 5100 G, with an RF power of 1500 W. Maximum Ar+ ion flux of 7.8 × 10²³ m^–2 s^–1 with a bright blue core plasma was obtained at a high B₀ of 2700 G and an RF power of 1500 W without bias. Plasma energy and mass spectrometer studies indicate that Ar⁺ ion-beams of 40.1 eV are formed, which are supersonic (~3.1c _s). The effect of Ar HWP discharge cleaning on the wall conditioning are investigated by using the mass spectrometry. And the consequent plasma parameters will result in favorable wall conditioning with a removal rate of 1.1 × 10²⁴ N₂/m²h.

[en] The plasma electrons bombarding a plasma-facing wall surface can induce secondary electron emission (SEE) from the wall. A strong SEE can enhance the power losses by reducing the wall sheath potential and thereby increasing the electron flux from the plasma to the wall. The use of the materials with surface roughness and the engineered materials with surface architecture is known to reduce the effective SEE by trapping the secondary electrons. In this work, we demonstrate a 65% reduction of SEE yield using a velvet material consisting of high aspect ratio carbon fibers. The measurements of SEE yield for different velvet samples using the electron beam in vacuum demonstrate the dependence of the SEE yield on the fiber length and the packing density, which is strongly affected by the alignment of long velvet fibers with respect to the electron beam impinging on the velvet sample. Furthermore, the results of SEE measurements support the previous observations of the reduced SEE measured in Hall thrusters.

[en] The dual-frequency capacitively coupled plasma (DF-CCP) with inductive enhancement system is a newly designed plasma reactor. Different from the conventional inductively coupled plasma (ICP) reactors, now a radio frequency (rf) power is connected to an antenna placed outside the chamber with a one-turn bare coil placed between two electrodes in DF-CCP. This paper gives a detailed description of its structure. Moreover, investigations on some characteristics of discharges in this apparatus were made via a Langmuir probe

[en] A high growth rate fabrication of diamond-like carbon (DLC) films at room temperature was achieved by helicon wave plasma chemical vapor deposition (HWP-CVD) using Ar/CH₄ gas mixtures. The microstructure and morphology of the films were characterized by Raman spectroscopy and scanning electron microscopy. The diagnosis of plasma excited by a helicon wave was measured by optical emission spectroscopy and a Langmuir probe. The mechanism of high growth rate fabrication for DLC films by HWP-CVD has been discussed. The growth rate of the DLC films reaches a maximum value of 54 μm h⁻¹ at the CH₄ flow rate of 85 sccm, which is attributed to the higher plasma density during the helicon wave plasma discharge. The CH and H_α radicals play an important role in the growth of DLC films. The results show that the H_α radicals are beneficial to the formation and stabilization of C=C bond from sp² to sp³. (paper)

[en] In this study, the effects of plasma treatment parameters on surface morphology, chemical constituent, dyeability and color fastness of silk fabric were investigated. Atmospheric pressure glow discharge plasma generated with different applied voltages (0 kV to 45 kV) was used to treat the surface of silk fabrics. C I Natural Yellow 3 was used to dye untreated and plasma-treated silk fabrics. The physical analysis based on scanning electron microscopy showed that the surface of silk fabrics was affected by plasma treatment. The chemical analysis was investigated with x-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The results showed that the content of C 1s decreased with the increasing applied voltage, the content of N 1s and O 1s increased with the increasing applied voltage. The increasing K/S values represented that the dyeability of silk fabrics was improved after plasma treatment. The color fastness to dry and wet rubbing was decreased after plasma treatment. (paper)

[en] We have investigated the microstructure and electrical properties of HfTaON high-k films deposited on n-type Si (1 0 0) substrate using a dual ion beam sputtering deposition technique (DIBSD). It is worth noting that HfO₂ begin to precipitate from four-compound HfTaON and crystallize as a monoclinic phase after annealing at 1100 °C. From FTIR spectra, one strong absorption peak at 512 cm^-1, which is characteristic of the HfO₂ monoclinic structure is also observed. The interfacial SiO_x can be formed during the annealing procedure rather than sputtering process, and the increase of atomic percentage of Si-O bands and transition from SiO_x (x < 2) to SiO₂ are observed with the increase of annealing temperature. High efficiency HfTaON film prepared by novel DIBSD has a higher dielectric constant of 24 and lower leakage current of 2.28 × 10^-8 A at V_g = (V_fb - 1), as compared with that of SiO₂·· HfSiON·· HfTaO films with same thickness.

[en] Er-doped TiO₂ thin films have been prepared by dual-frequency magnetron co-sputtering with two targets composed of TiO₂ and Er₂O₃. The structural and optical properties of these thin films were investigated using various characterization techniques. X-ray photoelectron spectroscopy measurements show that the content of Er increases when the power on Er₂O₃ target increases. X-ray diffraction patterns indicate that the anatase TiO₂ peaks become weaker with the increasing power on Er₂O₃ target and the films tend to form amorphous structure. Scanning electron microscopy results show that the grain size decreases with the rise in Er content. UV–vis spectrophotometric analyses reveal that the values of band gap decrease from 3.35 ± 1.3% eV to 3.02 ± 1.3% eV with the increasing amount of Er from 0 at.% to 3.2 at.%. The red shift in the optical adsorption edge may contribute to a higher photocatalytic activity of TiO₂ thin films. - Highlights: • Using dual-frequency magnetron sputtering technology. • Co-sputtering process with two targets was used to deposit Er-doped TiO₂ thin films. • Offering more freedom in selecting and adjusting deposition conditions. • The photocatalytic activity of TiO₂ thin films may be improved by Er doping.