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At present, the application of ZnSnN2 as an active layer in optoelectronic devices is dramatically limited due to its high carrier concentration. It is suggested that off-stoichiometry of cations might be a promising cure. In this work, Zn-Sn-N films with 0.60, 0.67, and 0.85 Zn/(Zn + Sn) ratios were, respectively, fabricated by DC magnetron sputtering. In spite of off-stoichiometry, the films all exhibited a cation-disordered wurtzitelike ZnSnN2 dominated phase except that the crystallinity was decreased with an increasing Zn/(Zn + Sn) ratio. In agreement with the cation-disordered structure, all the Zn-Sn-N films illustrated Raman spectra of a phonon-glasslike characteristic. The refractive index of the films was increased with the Zn/(Zn + Sn) ratio over a wide wavelength range, for example, from 1.990 to 2.459 at the wavelength of 500 nm. The direct optical bandgap of the films varied from 1.36 to 1.68 eV. Most strikingly, an electron concentration of magnitude down to 1016 cm−3 and a very low resistivity down to 10−2 Ω cm were reached for 0.67 and 0.85 Zn/(Zn + Sn) films, respectively. It is highly desirable that both semiconducting and conducting characteristics can be achieved in the Zn-Sn-N material system, which is highly beneficial to its applications in various optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this work, amorphous praseodymium-doped In-Sn-Zn-O (ITZO-Pr) thin-film transistors (TFTs) were fabricated with improved negative-bias illumination stress (NBIS) stability under different radio frequency (RF) magnetron sputtering powers. The optimized ITZO-Pr TFTs presented field effect mobility ($\boldsymbol {\mu }_{\text{FE}}$) of 20.9 cm $^{2}\cdot {}\text{V}^{-1}\cdot {}\text{s}$ −1, steep subthreshold (SS) of 0.27 V/dec, and small threshold voltage shift (${\Delta } {V}_{\text{th}} = -2.12$ V) under NBIS (−20 V, 3600 s). All Pr-doped devices exhibited a reduction in light responsivity of more than one order of magnitude compared with ITZO TFTs. Moreover, after Pr doping, relaxation processes of photoelectrons changed and then the activation energy (${E}_{\text{a}}$) of light-induced electrons relaxation decreased, which enhanced the NBIS stability of ITZO TFTs effectively. [ABSTRACT FROM AUTHOR]

Amorphous gallium oxide (a-GaO x) thin films are fabricated via magnetron sputtering at room temperature by regulating the substrate bias voltage (V s) in a wide range (0 ~ -184 V). The effect of V s on the performance of a-GaO x films and their photodetector devices, such as the chemical composition, optical, morphological, and electrical properties, are systematically investigated. It's found that both the refractive index and the film relative mass density are highly dependent on the Ga/O ratio that can be effectively modified by the V s. And the subband trap density or/and microvoid defects in a-GaO x films can be largely reduced under a well-selected V s. The deep-ultraviolet photodetectors based on the optimized a-GaO x thin films show a responsivity of nearly 13 A/W with an ultrahigh UV/vis. rejection ratio. The research suggests that substrate bias voltage may be a feasibly subsidiary method for low-temperature magnetron sputtering technology with respect to the quality control of a-GaO x films. [ABSTRACT FROM AUTHOR]

In this work, we study the intrinsic connection between target quality and performance of sputtered In-Sn-Zn-O (ITZO) thin-film transistors. Using a dense target, the ITZO device overall performance can be improved synergistically. The optimized device exhibits a steep subthreshold swing of 0.13 V/decade, a high on/off current ratio of 2.47 × 108, a threshold voltage of −0.03 V, a saturation field-effect mobility (μFE) of 36.1 cm2/Vs, and a small threshold voltage shift (Δ Vth) of −0.55 V under negative bias stress (−20 V, 3600 s). In contrast, the μFE shows a reverse trend to Δ Vth when using a target with a relatively small density and poor crystallinity. In this case, although the amount of oxygen vacancy in the films can be reduced for better stability via increasing the sputtering power, the film density observably drops due to serious preferential sputtering, leading to smaller μFE. [ABSTRACT FROM AUTHOR]

Plasmonic structural colors, arising from resonance interactions between photons and metallic nanostructures, have been developed rapidly for high‐end applications. However, common structural color materials and fabrication methods usually have open plasmonic nanostructures and limited scalability, respectively. Here, a new scheme based on Ag nanowire arrays/SiO2 composite metamaterial films with subwavelength enclosed nanostructures involved that combine a dielectric gap layer and a metal mirror is presented. The whole stacked structure can be simply prepared only via magnetron sputtering without any other procedures. Specifically, by changing deposition parameters, the geometry size and sub‐10 nm periodic parameters of the structure unit cell array can be finely tuned in a controllable and reproducible way. By experiments and simulations, it is demonstrated how interwire coupled plasmonic transverse modes in vertically orientated nanocavity arrays control multiple nanocavity standing‐wave resonances at visible wavelengths, generating three primary colors‐included bright and saturated colors across a wide gamut. Large‐area and uniform structural colors, whether on rigid or flexible substrates, show angle‐insensitive and air‐stable features. In a wider perspective, this work suggests that the material scheme and fabrication advances represent a robust platform for plasmonic color designing, theory exploring, and large‐scale manufacturing. [ABSTRACT FROM AUTHOR]

Fully transparent InZnO thin-film transistors (TFTs), with either a bottom gate or an in-plane gate device structure, were fabricated using the solution-processed SA proton conducting films as gate dielectrics. The self-assembled InZnO channel with different thickness by the gradient shadow mask was fabricated during the same batch radio-frequency magnetron sputtering. The threshold voltage can be modulated from −0.25 to +0.12 V and from −0.07 to +0.25 V by the channel layer thickness variations for the vertically-coupled and laterally-coupled InZnO TFTs, respectively. Accordingly, these InZnO TFTs can operate in either depletion or enhancement mode on the same chip. A general expression of the turn-on voltage in relation to the channel thickness is derived. The device performance with an on/off current ratio of ≥1.5 × 106, a subthreshold swing of down to 70 mV/decade, and a field-effect mobility of up to 34.3 cm2/V · s is exhibited. Our results demonstrate that the same batch channel processing is potentially applied in logic circuits or functional electronics. [ABSTRACT FROM AUTHOR]

Abstract: An amorphous carbon thin film, with through-pores of several tens of nanometers in size, has been synthesized by annealing magnetron sputtered nitrogen-doped carbon thin films at elevated temperature in an inert atmosphere. Based on this nanoporous carbon film, we first report forming-free resistive switching in a two terminal device containing ready-made metal nanofilaments. Such nanoporous carbon-based resistance memory device shows low operation voltages and good endurance and retention performance. [Copyright &y& Elsevier]

A solar selective absorber coating of CrN x O y /SiO2 was prepared on Cu (Si) substrate using DC reactive magnetron sputtering technique. The coating exhibits a high absorptivity (α) of 0.947 and a low emissivity (ε) of 0.05 at 80°C. The spectral selectivity (α/ε) of the coating on Cu substrate is stable (0.930/0.073) even after heat-treatment at 278°C in air for 300h, but decreased (0.904/0.135) at 278°C for 600h. The determinants to govern the thermal stability were investigated by micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) measurements, which reveal that the element diffusion whether throughout all the stacked layers or near the interface region, the chemical interactions adjacent to the interface, and the interface width broadening are the Achilles' heel for the solar thermal coatings to sustain high thermal stability. [ABSTRACT FROM AUTHOR]