|Commenced in January 1999||Frequency: Monthly||Edition: International||Paper Count: 3|
Silver (Ag) nanoparticles (NPs) patterned SiOx nanowire (NW) arrays were synthesized on Si substrates by using a catalytic free technique called Glancing Angle Deposition (GLAD) technique. The successful growth of Ag patterned SiOx NWs on Si substrate is manifested through the field emission gun scanning electron microscopy with energy dispersive spectroscopy analysis and transmission electron microscope analysis. The Ag patterned SiOx NW consists of ~140 nm SiOx NW and ~20 nm Ag NPs. The TEM image also reveals the crystalline nature of Ag NPs and amorphous nature of SiOx NWs. The photoluminescence spectrum of the sample shows broad band emission exhibiting peak values at 374 nm and 667 nm at excitation wavelength of 250 nm that corresponds to Ag NPs and SiOx NWs, respectively. The Ag patterned SiOx NWs exhibit a low bandgap of 1.9 eV due to the significant reduction in the recombination of holes and electrons in the SiOx layer. The Ag patterned SiOx NW-based device shows improvements in photodetection under white-light illumination compared to dark condition. This occurs due to the hole trapping process at the metal- Ag patterned SiOx NW interface states that efficiently reduced the depletion width under reverse bias. Moreover, the Schottky height at the junction is also reduced, which in turn enhanced the electron tunneling process. It is also interesting to know that the device exhibited a low turn on voltage (~0.6 V) as well as a fast response of 0.16 s (rise time) and 0.17 s (fall time) which makes it a potential application in optoelectronics.
Fused deposition modeling (FDM) gains popularity in recent times, due to its capability to create prototype as well as functional end use product directly from CAD file. Parts fabricated using FDM process have mechanical properties comparable with those of injection-molded parts. However, performance of the FDM part is severally affected by the poor mechanical properties of the part due to nature of layered structure of printed part. Mechanical properties of the part can be improved by proper selection of process variables. In the present study, a comparative study between unidirectional and bidirectional raster angle has been carried out at a combination of different layer height and raster width. Unidirectional raster angle varied at five different levels, and bidirectional raster angle has been varied at three different levels. Fabrication of tensile specimen and tensile testing of specimen has been conducted according to ASTM D638 standard. From the results, it can be observed that higher tensile strength has been obtained at 0° raster angle followed by 45°/45° raster angle, while lower tensile strength has been obtained at 90° raster angle. Analysis of fractured surface revealed that failure takes place along with raster deposition direction for unidirectional and zigzag failure can be observed for bidirectional raster angle.