[en] This study explored the removal of silicon nitride using KrF laser ablation technology with a high threshold fluence of 990 mJ/cm². This technology was used for contact hole patterning to fabricate SiN_x-passivation-based amorphous-silicon thin films in a transistor device. Compared to the photolithography process, laser direct patterning using KrF laser ablation technology can reduce the number of process steps by at least three. Experimental results showed that the mobility and threshold voltages of thin film transistors patterned using the laser process were 0.16 cm²/V-sec and 0.2 V, respectively. The device performance and the test results of gate voltage stress reliability demonstrated that laser direct patterning is a promising alternative to photolithography in the panel manufacturing of thin-film transistors for liquid crystal displays. - Highlights: ► KrF laser ablation technology is used to remove silicon nitride. ► A simple method for direct patterning contact-hole in thin-film-transistor device. ► Laser technology reduced processing by at least three steps

[en] Cu-mesh transparent conductive film offers high conductivity and transparency, making it suitable for electromagnetic interference (EMI) shielding. However, the oxidation of the Cu-mesh transparent conductive film in the atmosphere, limits its use. To solve this problem, the ITO/Cu-mesh transparent conductive film structure is employed to avoid Cu oxidation and improve EMI shielding performance in this study. By stacking the Cu mesh with ITO film, the resistivity and average X-band EMI shielding effectiveness can be improved from 7.89 9 10^-7 Ω cm and - 23.4 dB to 7.35 9 10-7 Ω cm and - 25.6 dB, respectively. Additionally, we performed a 72-h salt corrosion test on the samples in accordance with the ASTM B-117 guidelines; the ITO/Cu-mesh film structure does not observe any obvious etching or oxidation. The results show that ITO films are suitable as a protective Cu-mesh coating and confirming that ITO/Cu-meshes have excellent weather resistance and EMI shielding effectiveness. (author)

[en] Metal induced crystallization (MIC) can be generated by using a silver nanoparticles (AgNPs) solution spin coated on amorphous silicon (a-Si) film, and annealing the sample in a furnace under vacuum. Because nanoscale metal has a large specific surface area, its catalytic effect is enhanced, resulting in a low processing temperature. Thus, a poly-Si thin film with a high crystalline fraction can be obtained by using AgNPs induced crystallization. In this study, the size and annealing time of AgNPs are discussed. According to the results, the grain size of the poly-Si thin film produced using AgNPs induced crystallization was more uniform than that of the film obtained by employing traditional thermally evaporated Ag induced crystallization. Smaller AgNPs size and long annealing time enhance the crystallization of poly-Si thin film. Applying an annealing temperature of 550 °C for 480 min with 10 nm of AgNPs yielded a crystalline fraction of 75%. (paper)

[en] The Ni-metal-induced crystallization (MIC) of amorphous Si (α-Si) has been employed to fabricate low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Most studies have focused only on reducing Ni contamination because Ni residues cause high leakage current in MIC–TFTs. Also of concern is the source/drain (S/D) series resistance, which degrades the device performance (driving ability) that might vary with the Ni concentration in MIC–TFTs. Improving the driving ability of MIC–TFTs requires a detailed understanding of how Ni residues affect S/D series resistance. This study investigates how Ni concentration affects S/D series resistance by using the transmission line method. The results of this study provide further insight into how Ni concentration and resistance are related. The results show that the S/D series resistance and channel resistance decreased with a reduction in Ni concentration in MIC poly-Si because of better crystalline quality and lower degradation of the donor concentration. This phenomenon was caused by the Ni concentration forming less NiSi₂ nucleation sites to generate a large grain size; Ni atoms serve as acceptor-like dopants in silicon, which counteract with the effects of n-type doping, subsequently reducing the donor concentration in the S/D region. - Highlights: ► Channel and source/drain resistance were decreased with reducing Ni concentration. ► Low Ni concentration formed less nucleation site of NiSi₂ to cause large grain size. ► Ni serves as acceptor to counteract the effects of n-type doping in source/drain region

[en] Highlights: • Silver nanowires (AgNWs) light scattering layer is used in dye-sensitized solar cell. • TiO₂ compact layer (CL) is covered on AgNWs to suppress carrier recombination. • TiO₂ CL/AgNWs stacking layer can improve the electrical characteristics. • TiO₂ CL/AgNWs films are favorable for high performance dye-sensitized solar cells. In this study, indium tin oxide (ITO) glass was coated with silver nanowires (AgNWs) by ultrasonic spray coating to roughen the ITO surface, yielding a surface texture comparable to that obtained by chemical etching. A compact layer (CL) of titanium dioxide (TiO₂) was coated on the AgNWs/ITO surface by sputtering to improve the properties of dye-sensitized solar cell (DSSC). A TiO₂ CL was used as a protective layer on AgNWs to prevent oxidation and increase the adhesion of AgNWs. The TiO₂ CL also effectively inhibited the carrier recombination between the electrolyte solution and ITO interface, thereby improving the photoelectric conversion efficiency (η) of the DSSC device. The experiment results indicated that the η of DSSC devices with a CL deposited under the working electrode increased from 4.06% to 4.37%. The integration of the CL and AgNWs to CL/AgNWs/ITO structure increased the η of DSSC devices further to 4.59%. Electrochemical impedance spectroscopy was performed to analyze two DSSC structures, namely CL/ITO and CL/AgNWs/ITO; the electron lifetime increased from 0.35 ms to 0.55 ms and the charge collection rate increased from 64.5% to 75.2%. Therefore, CL/AgNWs/ITO working electrode structure can effectively improve the performance of DSSC devices.

[en] NiVOx thin films were deposited by pulse magnetron sputtering using an alloy target of 8 at%V and 92at%Ni to prevent the ferromagnetic disadvantage that is associated with the use of a pure Ni metallic target. Their surface properties and related electrochromic behaviors were also examined systematically by X-ray diffraction (XRD), X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy. Additionally, the optical density and modulation of the NiVOx films were analyzed using a UV/VIS spectrophotometer (UV–Visible). Electrochromic tests were conducted using an electrochemical analyzer. Experimental results reveal that electrochromic properties heavily depended on the crystalline phase, thickness, chemical composition and microstructure, which were controlled by varying the plasma power and the argon/oxygen ratio. As well as demonstrating that V can significantly reduce the ferromagnetic effect, stabilize the plasma state and produce NiVOx films with a high percentage of Ni²⁺, XPS and XRD analyses reveal that Ni²⁺, Ni³⁺, V⁴⁺ and V⁵⁺ co-exist in the NiVOx films thus produced non-ideal stoichiometric compounds at an argon/oxygen ratio of three. Hence, films fabricated at Ar/O₂ = 3 had the optimal electrochromic properties, with high optical modulation, high optical density and the lowest color memory effect at wavelengths of 400, 550 and 800 nm. - Highlights: ► The morphology of NiVOx film becomes coarser as the Ar/O₂ ratio increases. ► Reducing the Ar/O₂ ratio transforms the crystalline phase from (111) to (200). ► NiVOx films exhibit coarse surface and comprise non-ideal stoichiometric compounds. ► The optical density of NiVOx films shows potential in electrochromic applications

[en] In this study, we prepared titanium oxide (TiO₂) compact-layer thin films (thickness: 50 nm) on an indium tin oxide (ITO)/glass substrate by liquid-phase deposition (LPD) for the dye-sensitized solar cell (DSSC). We used a deposition solution of ammonium hexafluoro-titanate and boric acid (H₃BO₃) for the TiO₂ film. We varied the concentration of H₃BO₃ from 0.4 to 0.7 M to control the deposition rate, surface roughness, and refractive index of the TiO₂ film. Based on the results of X-ray diffraction and transmission electron microscopy, the TiO₂ films all possessed the polycrystalline feature with (101), (004), (200), (105), and (211) planes. After the LPD deposition, we can observe that the formation of the transition-layer existed in the TiO₂ film. The transition-layer is analyzed as In and Sn co-doped TiO₂ film, which is caused by the diffusions of In³⁺ and Sn⁴⁺ ions from the ITO substrate. From the depth profiles of X-ray photoelectron spectroscopy, the thickness of the transition-layer increased with a decrease of the boric acid concentration. At the optimum H₃BO₃ concentration of 0.5 M, we obtained the following photovoltaic properties: a short circuit current density (J_sc) of 11.41 mA/cm², an open circuit voltage (V_oc) of 0.73 V, a fill factor (ff) of 0.63, and an efficiency (η) of 5.24%. The LPD-TiO₂ compact-layer between the ITO and the DSSC photo-electrode can reduce the number of carrier recombinations and improve transmittance in the visible light region. The TiO₂ compact-layer prevents electron transport to the electrolyte and results in a higher J_sc. Moreover, the LPD-TiO₂ compact-layer can enhance interface adhesion and improve the series resistance.

[en] Silver nanowires were synthesized by the polyol method employing ethylene glycol, Poly(N-vinylpyrrolidone) (PVP) and silver nitrate (AgNO₃) as the precursors. Most of the studies used metal salts (PtCl₂, NaCl) as seed precursor to synthesize the silver nanowires. In the study, the metal salts were not used and the concentration of capping agent was changed to observe the aspect ratio of silver nanowires. The experimental results showed that controlling synthesis temperature, Poly(N-vinylpyrrolidone) (PVP) molecular weight, reactant concentrations, and addition rates of AgNO₃ affects the growth characteristics of silver nanowires. Field-emission scanning electron microscopy, UV–vis spectrophotometry, and X-ray diffractometry were employed to characterize the silver nanowires. As increasing the concentration of PVP, the silver nanowire diameter widened and resulted in a smaller aspect ratio. We successfully prepared silver nanowires (diameter: 170 nm, length: 20 μm). The silver nanowire thin film suspension showed high transmittance, low sheet resistance, and may be used for transparent conductive film applications. - Graphical abstract: The FE-SEM image shows that nanostructures with considerable quantities of silver nanowires can also be produced when the PVP (Mw=360 K)/AgNO₃ molar ratio was 2.5. - Highlights: • The polyol method was used to synthesize of silver nanowire. • The metal seed precursors were not used before synthesizing the silver nanowires. • The silver nanowire diameter and length was 170 nm and 20 μm, respectively. • Silver nanowire film with high transmittance (>85%) and low sheet resistance (<110 Ω/sq)

[en] This study used activated carbon doped with one-dimensional silver nanowires with different diameters as the electrode paste for electric double-layer capacitors and used ultrasonic spray coating to fabricate thin-film electrodes. The paste can be refined through the ultrasonic shock frequency in ultrasonic spraying, which is a technology that can effectively increase the specific surface area and porosity of activated carbon, and is favorable for the adsorption–desorption of ions in the electrolyte to achieve higher charge storage. For electrochemical analysis, the working potential window was set between −0.75 and 0.75 V for cyclic voltammetry and galvanostatic charge–discharge. Electrochemical impedance spectroscopy and cycle count were measured. The experimental results of the prepared film electrodes with silver nanowires of different diameters showed that the silver nanowire that is doped solely with activated carbon electrode paste as the conductive material can improve the supercapacitor’s electrochemical properties. The undoped 186 F g⁻¹ increased by 38.7% to 258 F g⁻¹, whereas the charge-transfer resistance dropped by 35.7%. Moreover, after 1000 cycles of testing, 93.2% of the capacitance value was retained. It proved that activated carbon-film electrodes doped with 500 nm silver nanowires can improve the capacitance and stability of the supercapacitor.

[en] Silver nanowires were synthesized using a polyol process by employing ethylene glycol, poly(N-vinylpyrrolidone), and silver nitrate as precursors. The concentration of silver nitrate was varied to study the resulting changes in aspect ratios of silver nanowires. The experimental results indicated that the growth characteristics of silver nanowires were affected by the synthesis temperature, the concentration of silver nitrate, and the rate at which silver nitrate was added. Field-emission scanning electron microscopy, UV–visible spectrophotometry, and X-ray diffractometry were employed to characterize the silver nanowires. As the concentration of silver nitrate was reduced, the diameters of the silver nanowires decreased, increasing the aspect ratio. The optimal diameter and length of the silver nanowires were 100 nm and 20 μm, respectively. A thin film composed of silver nanowires exhibited average transmittance of 92.15% at visible wavelengths and a sheet resistance of 20 Ω/sq; such a film could be used as a transparent conductive film in commercial applications. - Highlights: • Using a polyol method to synthesize of silver nanowire • Concentration effect of silver nitrate on the synthesis was discussed. • Seed precursors are not used during the silver nanowire synthesizing. • The silver nanowire diameter and length were 100 nm and 20 μm, respectively. • High transmittance and low sheet resistance of silver nanowire film can be obtained