Abstract: A secondary lens includes a first face on which a concentrated light beam output from a concentrating lens is incident and a second face from which the concentrated light beam output from the concentrating lens is output to a photovoltaic cell. The secondary lens guides incident light to the photovoltaic cell through an optical refractive face provided on the first face. A cross-sectional area of the first face in a direction perpendicular to an optical axis (Ax) of the concentrated light beam monotonically increases as the cross-sectional area approaches from a side of the first face closer to the concentrating lens to a side of the first face closer to the photovoltaic cell. At least one point of inflection at which an angle of inclination (?) of the first face with respect to a plane perpendicular to the optical axis decreases as the angle of inclination (?) approaches from the side of the first face closer to the concentrating lens to the side of the first face closer to the photovoltaic cell is provided.

Abstract: A concentrated solar cell has a sealing portion (12) provided on a receiver substrate (102) so as to cover a solar cell element (101) provided on the receiver substrate (102), and an optical member (13) that is provided on the sealing portion (12) and concentrates sunlight on the solar cell element (101). The optical member (13) is configured so as to include an optical refraction portion (131) having a curved face for refracting and concentrating sunlight, a concentrated light emission portion (133) that is arranged in close contact with the sealing portion (12) such that the sunlight concentrated by the optical refraction portion (131) is emitted toward the solar cell element (101), and an optical base portion (132) arranged between the optical refraction portion (131) and the concentrated light emission portion (133).