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A membrane material based on polyamide-imide (PAI) has received a great attention lately due to its thermal resistance, outstanding mechanical property, and low thermal expansion coefficient. In this study, we have focused on the preparation of porous PAI nanofiber membranes (PNMs) for water treatments. The preparation of PNMs was completed via the electrospinning method using PAI in a mixed solvent of dimethylacetamide and tetrahydrofuran. The resulting PNMs were then thermally treated to improve mechanical properties. These PAI-based membranes were characterized by scanning electron microscope, tensometer (tensile strength and elongation), pore characteristic, contact angle analyzer (contact angle), and dead-end cell device (water flux). We noticed that the pore diameter (1.0–0.3 μm) of PNMs was systematically controlled by simply increasing the number of PNMs layers. As these nanofiber membranes were found to be highly hydrophobic, we also attempted to prepare hydrophilic PNMs with a PAI solut...

Maskless random reactive ion etching (RIE) texturing employing a SF6/O2/Cl2 gas mixture was investigated in order to achieve higher efficiencies in multicrystalline silicon (mc-Si) solar cells. Triangular pyramid structures with an aspect ratio of 1 were formed and, when the RIE power increased, the average reflectance was reduced by about 1.46% per 10 W. This was due to the increased density of the surface features. The performances of all of the RIE-textured mc-Si solar cells were improved compared with that of the reference cell. Among them, the 110 W cell, which had a 0.6% higher efficiency than the reference cell, had the highest efficiency of 16.82%. An impedance analysis was carried out to determine series resistance (R s), shunt resistance (R sh), and junction capacitance (C j). Interestingly, the cell with higher efficiencies and higher structure densities had higher linear reverse currents.