Patent ID: 8404513
Filing Date: 2013-03-26
Classification: H01L,Y02E

Abstract:
1. A method for generating electric power with use of a solar cell, the method comprising steps of: (a) preparing the solar cell comprising a condensing lens and a solar cell element, wherein the solar cell element comprises an n-type GaAs layer, a p-type GaAs layer, a quantum tunneling layer, an n-type InGaP layer, a p-type InGaP layer, a p-type window layer, an n-side electrode, and a p-side electrode; a Z-direction denotes the direction of the normal line of the p-type GaAs layer; an X-direction denotes a direction orthogonal to the Z-direction, the n-type GaAs layer, the p-type GaAs layer, the quantum tunneling layer, the n-type InGaP layer, the p-type InGaP layer, and the p-type window layer are stacked along the Z-direction in this order; the p-type window layer is made of a p-type compound semiconductor having a wider bandgap than InGaP, the n-side electrode is electrically connected with the n-type GaAs layer; the p-side electrode is electrically connected with the p-type InGaP layer; the n-type GaAs layer is divided into a GaAs center part, a first GaAs peripheral part, and a second GaAs peripheral part; the GaAs center part is interposed between the first GaAs peripheral part and the second GaAs peripheral part along the X-direction; the first GaAs peripheral part and the second GaAs peripheral part have a shape of a layer, the n-type InGaP layer is divided into an InGaP center part, a first InGaP peripheral part, and a second InGaP peripheral part; the InGaP center part is interposed between the first InGaP peripheral part and the second InGaP peripheral part along the X-direction; the first InGaP peripheral part and the second InGaP peripheral part have a shape of a layer, the following inequation set (I) is satisfied: wherein d d d d d d w w w w (b) irradiating a region S which is included in the surface of the p-type window layer through the condensing lens with light in such a manner that the following inequation (II) is satisfied so as to generate a potential difference between the n-side electrode and the p-side electrode: wherein w w the first GaAs center part overlaps the region (S) when seen from the Z-direction.