the standard silicon photovoltaic module consisted of a front cover glass (asahi glass co.,ltd., soda lime glass, 3.2 mm thickness, 180 mm * 180 mm), tow films of commercial eva (fast-cure-type, 0.45 mm thickness ) as the encapsulant, the n-type silicon cell, and a commercial back sheet whose structure is polyvinyl fluoride (PVF)/polyethylenc terephthalate (PET)/PVF.