Characterization and Testing of the Locally Fabricated Encapsulants in Egypt for Commercial Photovoltaic Modules Production

In this work, different locally fabricated adhesive materials were examined to be used as an encapsulant for producing of photovoltaic modules. All the selected samples were characterized by FT-IR spectroscopy, TG instrument, UV-VIS spectrophotometer and electrical resistance meter. In addition, all the samples under investigation were examined by aging tests according to IEC standards for testing their stability and durability. The polymethacrylate material with UV stabilizer can be considered as an excellent commercial candidate for photovoltaic module encapsulant due to its high optical transmission, good adhesive strength with the glass, high photo-stability, high thermal stability and high electrical insulation (electrical resistance).

Electrospun Composite Nanofiber Transparent Conductor Layer for Solar Cells

ABSTRACTDeveloping a durable and scalable transparent conductor (TC) as an electrode with high optical transmission and low sheet resistance is a significant opportunity for enabling next generation solar cell devices. High performance fibrous composite materials based on a carrier polymer with embedded functional nanostructures have the potential to serve as a TC with high surface area that can be deposited by the novel and scalable process of electrospinning. This work presents the development of a fibrous TC, where polyacrylonitrile (PAN) is used as a carrier polymer for multi-walled carbon nanotubes (MWCNT) to create electroactive nanofibers 200-500nm in diameter. Once carbonized, thin layers of this material have a low sheet resistance and high optical transmission. It is shown that in a two stage carbonization process, the second stage temperature of above 700C is the primary factor in establishing a highly conductive material and single layers of nanofibers are typically destabilized at high temperatures. A high performance TC has been developed through optimizing carbonization rates and temperatures to allow for single nanofiber layers fabricated by electrospinning MWCNT/PAN solutions onto quartz. These TCs have been optimized for concentrations of MWCNTs less than 20% volume fraction with well above 90% transmissivity and sheet resistances of between .5-1kohm/square. The required MWCNT loading is well below that for TCs based on random networks of MWCNTs.

Large Scale Translucent Y-α-Sialon Ceramics Prepared by Two-Steps Hot Pressing

Large scale translucent yttrium-doped α-sialon (80 mm in diameter) with the composition of Y0.4Si9.6Al2.4O1.2N14.8 (m=1.2 and n=1.0) was prepared by two-steps hot pressing sintering (first heating to 1850 °C holding for 30 min, then continue heating to 1900 °C holding for 30 min) at 25 MPa in nitrogen, and the optical property was approached over the wavelength range 900-5000 nm. The results showed that dense sample was obtained and its assemblage only consisted of single α-sialon phase. The large scale sialon had uniform and higher infrared transmittance property. The maximum infrared transmittance for 1.0 mm thick specimen could reach 66% at 3200 nm. It is attributed to the dense, uniform, equaxed microstructure. In addition to high optical transmission property, the sample showed higher hardness of 20 GPa and better fracture toughness of 5 MPa•m1/2.