Investigation of Nanomaterial Based Photovoltaic Panel Packaging Material

In this research, nanomaterial-based packaging materials for photovoltaic (PV) panels are investigated. A hydrophobic/anti-reflective surface coating which not only repels water from the top glass of a PV panel but at the same time reduces its light reflectance is investigated. COMSOL simulation results indicate that taller ellipsoid rod (aspect ratio = 5) reflects less light than shorter rod (aspect ratio = 0.5) in the desired spectrum for solar energy harvest from 400nm--700nm. The addition of a polymer layer on these ellipsoid rods broadens the light incident angle from 23° to 34°, from which light can be efficiently absorbed. Based on optical simulation results and surface wetting mechanics, the design of a combined anti-reflective and hydrophobic surface for PV panel is investigated. Deep reactive-ion and wet etching are used to fabricate a unique ellipsoid-shaped silicon stamp on a silicon wafer. The nano-imprinting process yields a super hydrophobic silicone coating on glass that can improve light transmittance by 1.5% with a water contact angle larger than 150°. The light transmittance of nano silica coating with a surface assembled monolayer of 1H,1H,2H,2H-Perfluorododecyltrichlorosilane prepared from a sol-gel growth is 3% higher (400nm--700nm) than that for a bare glass slide. This coating passed the MIL-STD-810G felt abrasion test, 100 cycles of temperature cycling test (--45 °C--120 °C), heat endurance test (200 °C for 500 hours), and UV test (2.7mW/cm 2 UVA radiation for 1000 hours).;The second PV packaging material investigated is the nano-particle embedded EVA encapsulation. To block the migration of harmful free radicals that cut the co-polymer network into smaller molecules by chemical reaction in EVA, nano silica particle or functionalized nano diamond particles are embedded into EVA sheets. A difference of 1% light transmittance between pristine EVA sheet and nano particle embedded EVA sheet indicates that the nano particles slow down the degradation of EVA after 2.7 mW/cm2 UVA radiation for 2 months. The embedded EVA sheet exhibits better adhesion strength on glass surface indicated by a conventional tape peeling test.