Patent ID: 8748737

Claim:
A concentrator photovoltaic device comprising: an optical concentrator for concentrating sunlight; a solar battery cell; a homogenizer which is provided above the solar battery cell such that a bottom surface thereof faces the solar battery cell and which guides sunlight concentrated by the optical concentrator to the solar battery cell; a sealant which covers a side surface of a lower portion of the homogenizer and the solar battery cell; and a light transmission preventing layer provided between the sealant and the homogenizer and integrally formed on a lower side surface and a bottom surface of the homogenizer, wherein the homogenizer has a trapezoidal shape in which a sectional area at the optical concentrator side is larger than a sectional area at the solar battery cell side, a relationship of n t >n f >n t is satisfied among a refractive index n h of the homogenizer, a refractive index n f of the sealant, and a refractive index n t of the light transmission preventing layer, a thickness (H) of the light transmission preventing layer is equal to or larger than 0.1 mm and equal to or smaller than 1.2 mm, and a relationship of 0.5≦b/a<1.0 is satisfied between a height (b) of the light transmission preventing layer which is defined as the distance between a bottom edge of the homogenizer and a top most edge of the light transmission preventing layer and a height (a) of the sealant which is defined as the distance between the bottom edge of the homogenizer and a top most edge of the sealant.