Abstract: A solar cell encapsulated with an encapsulating material which is a non-crystalline or low-crystalline ?-olefin-based copolymer or its composition (I). The composition (C) can contain 50 to 100 parts by weight of non-crystalline ?-olefin polymer (A) which meets the following requirements: (a) the ?-olefin having 3 to 20 carbon atoms is not less than 20 mol %, (b) practically no melt peak as measured by a differential scanning calorimeter is observed, and (c) the Mw/Mn is not more than 5, and 50 to 0 parts by weight of crystalline ?-olefin polymer (B) (the total of (A) and (B) being 100 parts by weight). The non-crystalline or low-crystalline ?-olefin copolymer may also have a crystallinity of not higher than 40% as measured by use of X rays.

Abstract: Encapsulating material for solar cells which facilitates fabricating solar cell modules and has excellent transparency, heat resistance, flexibility, etc., and a solar cell modules. More specifically, the present invention provides encapsulating material for solar cells comprising a non-crystalline or low-crystalline a-olefin-based copolymer or its composition (I). In a preferred embodiment, the aforementioned copolymer or its composition (I) is a resin composition (C) containing 50 to 100 parts by weight of non-crystalline ?-olefin polymer (A) meeting the following requirements: (a) the ?-olefin having 3 to 20 carbon atoms is not less than 20 mol %, (b) practically no melt peak as measured by a differential scanning calorimeter is observed, and (c) the Mw/Mn is not more than 5, and 50 to 0 parts by weight of crystalline ?-olefin polymer (B) (the total of (A) and (B) being 100 parts by weight).