Papers by Keyword: Buffer Layer

Abstract: MIG welding overlaid austenitic stainless steel on low alloy Q345B. The overlay cladding comprises a transition layer and corrosion resistant layer. Overlaying specimens of transition layer with different thicknesses were prepared. The mechanical properties of joints were tested by micro-hardness, bending test and other methods. The results showed that the mechanical properties of specimen with ER309L welding wire as transition layer did not have splitting phenomena after being bended. There were no cracks. However, the specimen without transition layer had small crack or tiny cracks. When the transition layer thickness is changed, the performance of overlay cladding is essentially unchanged. The organizations of overlay cladding in four groups of specimens are similar, which are composed of austenite and ferrite, and ferrite was mostly distributed in strips and blocks.

Abstract: The weld overlay technology of high strength low alloy steel (HSLA) and austenitic stainless steel is widely applied in such fields as petroleum, chemical industry and energy, and its service environment is of high temperature and corrosion. As the matching performance is often poor for both austenitic stainless steel and high strength low alloy steel, cavities and crackles occur easily at the joints, which cause brittle fractures with dangerousness to some extent. So in the present study, the metal-inert gas welding (MIG) is used to clad the austenitic stainless steel to HSLA. In the experimental group, 4mm buffer layer (E309L) and 8mm cladding layer (E347L) were successively cladded on the substrate (Q345B), while 12mm cladding layer was directly deposited on the substrate in the control group. The hot corrosion tests were done, and through the scanning electron microscope (SEM), we observed the cross-sectional morphology. By the X-ray diffraction (XRD), we analyzed ingredients of the corrosion products. The corrosion products in the experimental group mainly consist of iron and nickel oxides, while the products are mainly iron complex compound and salt in the control group. The SEM results show the area near the welding seam of the specimens without buffer layer had been corroded severely. However, only a slight corrosion occurs adjacent to the welding seam. This demonstrates that the buffer layer can protect the specimens from being corroded.

Abstract: The Ga-doped zinc-oxides (GZO) as the transparency conductive oxide is the good candidate for substituting ITO. The buffer layer SiO_x could improve the quality of GZO thin film. The atmospheric pressure plasma multi-jets (APPMJ) system with three jets was designed and applied for SiO_x deposition process. The deposition thickness of three jets was 2.5 times higher than that of single jet, and the uniformity was less than 5% for the area 100mm². GZO thin film with SiO_x buffer layer had 3% decreases in resistivity compared to GZO thin film due to the increasing of mobility. The SiO_x/glass fabricated APPMJ system will be a good alternative substrate to bare glass for producing high quality GZO film for advanced electro-optic applications.

Abstract: ZnO: Al film was deposited on TPT substrate with SiO₂ buffer layer by RF magnetron sputtering. The obtained film had a hexagonal structure and highly (002) preferred orientation. The lattice constant distortion of the film with buffer layer was decreased and the compressive stress was 0.779GPa. The carrier concentratio reached to 3.15×10⁺²⁰/cm3. The resistivity of ZAO film with SiO₂ buffer layer was about 9.2×10^-3 Ω·cm and the average transmittance was over 72% in the range of 380~900nm.

Abstract: ZnS is a promising material to substitute the CdS layer into the thin film solar cells, given its high reflectance and its wide wavelength to catch the solar radiation. ZnS films prepared by chemical bath technique present a low cost and a simple method to produce controlled films. However, the films quality depends on the chemical reagents and their concentration used. In this work, different chemical conditions are proposed for preparing ZnS films by the chemical bath deposition (CBD) technique. ZnS thin films were deposited at 80 °C by CBD by changing the concentrations of the chemical reagents NH₄NO₃, KOH, and maintaining the concentrations of ZnCl₂ and thiourea (SC(NH₂)₂) in the chemical bath. The best conditions of the chemical reagents under the different deposition times (60 to 140 min) were obtained as a result of the experimentation done in order to produce ZnS thin films with good optical quality. The mean optical band gap energy measured on the prepared ZnS films was 3.77 eV, with a film thickness between 40 and 63 nm. The crystalline structure of films was amorphous as obtained by x-ray diffraction analysis. The surface roughness measured on the ZnS films was between 5 to 13 nm as obtained from atomic force microscopy images. Energy Dispersive Spectroscopy analysis show a Zn/S atomic ratio between 0.05 to 0.64.

Abstract: Thin film solar cells (TFSC) are the most potential for development of new and renewable clean energy. The large-scale production and application of TFSC can ease the energy crisis and protect the environment for human. However, buffer layer is a critical layer, which determines the performance of TFSC. This paper reviews the preparation, mechanisms, deposition systems, and development of ZnS thin-film buffer layers and points out that CBD-ZnS thin film is the best buffer layer material taking place of CdS.

Abstract: In this paper, we explore the characteristics of bulk heterojunction solar cell based on poly (3-hexyl thiophene) [P3HT] and [6,6]-phenyl-C61-butyric acid methyl ester [PCBM] by introducing a buffer layer with device configuration of ITO/ZnO/P3HT:PCBM/Au. Nanostructured ZnO with individual diameter around 20-50 nm was used as the buffer layer and its effects on the short circuit current density, J_sc and open circuit voltage, V_oc were investigated. It was found that, the electrical characteristic of the organic solar cell was obviously changed by introducing the buffer layer. Solar cell characteristic with V_oc of 0.3939 V was obtained but the J_sc was very small. The surface topology of the P3HT:PCBM was investigated using an atomic force microscopy (AFM). ZnO nanoparticles were observed using a field emission scanning electron microscope (FESEM) and the electrical properties of the solar cell was measured using a solar simulator with a current – voltage (I-V) measurement system.

Abstract: This paper presents the results of optical characteristics of ITO thin film with different buffer layer thicknesses of SiO₂ and Nb₂O₅ for touch sensor application. SiO₂ and Nb₂O₅ buffer layers were deposited by using RF/DC magnetron sputtering equipment. Buffer layers were inserted between Glass and ITO layer. In order to compare with experimental results, Essential Macleod Program (EMP) was adopted. Based on EMP simulation, [Nb₂O₅/SiO₂/ITO] multi-layered thin film exhibited a high transmittance more than 85% in the visible region. The actual experimental results also showed transmittance more than 85% in the visible region, indicating the simulated results were well matched with experimental ones. The sheet resistance of ITO based film was about 300ohm/sq..

Abstract: Build the model of motocross-style helmet with a dual - density and series-parallel EPS buffer layer and trial-produce helmet samples. Establish the impact experiment of the helmet model and obtain the values of HIC and Peak ACC based on the testing regulations of ECE R22.05. According to the analysis of the test results, the influence law of different EPS material densities to cushioning effect of the helmet was analyzed specifically. Experimental results show that the minimum values of HIC and Peak ACC can be obtained when the density of EPS is designed to be 0.06g/cm³; a dual - density and series - parallel EPS buffer layer has higher than 76 % of the energy absorption efficiency, and this buffer structure well reduces the values of HIC and Peak ACC, and provides effective protection for the head.

Abstract: This work reports on the analysis of thin-film copperindiumgalliumdiselenide (CIGS) solar cells by using Solar Cell Capacitance Simulator software (SCAPS). We have modeled a PV device, which consists in a CIGS absorber, a CdS buffer and a ZnO window layer. We have studied the behavior of CIGS absorber as a function of Gallium content by simulating the behavior of CIGS solar cells versus the Ga content in the absorber layer.