COMPOUND-SEMICONDUCTOR PHOTOVOLTAIC CELL AND MANUFACTURING METHOD OF COMPOUND-SEMICONDUCTOR PHOTOVOLTAIC CELL

摘要

A compound-semiconductor photovoltaic cell includes a compound-semiconductor substrate; a first photoelectric conversion cell formed on the compound-semiconductor substrate; a first junction layer formed on the first photoelectric conversion cell; a second junction layer joined to the first junction layer directly or indirectly; and a second photoelectric conversion cell joined to the first photoelectric conversion cell via the first and second junction layers, and arranged on a light incident side of the first photoelectric conversion cell in a light incident direction. Band gaps of the first and second photoelectric conversion cells are made smaller from the incident side toward a deep side in the light incident direction in order. A band gap of the second junction layer is greater than or equal to a band gap of the second photoelectric conversion cell. The second photoelectric conversion cell is a GaAs-based photovoltaic cell, and the second junction layer is a GaPAs layer.

主权项

1. A compound-semiconductor photovoltaic cell comprising:
a compound-semiconductor substrate; one or more first photoelectric conversion cells formed of a first compound-semiconductor material and laminated on the compound-semiconductor substrate; a first junction layer formed of a second compound-semiconductor material and laminated on the one or more first photoelectric conversion cells; a second junction layer formed of a third compound-semiconductor material and joined to the first junction layer directly or indirectly; and one or more second photoelectric conversion cells formed of a fourth compound-semiconductor material, joined to the one or more first photoelectric conversion cells via the first junction layer and the second junction layer, and arranged on a light incident side of the one or more first photoelectric conversion cells in a light incident direction, wherein band gaps of the one or more first photoelectric conversion cells and the one or more second photoelectric conversion cells are made smaller from the incident side toward a deep side in the light incident direction in order, in a case of a single second photoelectric conversion cell, a band gap of the second junction layer is greater than or equal to a band gap of the second photoelectric conversion cell, and in a case of plural second photoelectric conversion cells, the band gap of the second junction layer is greater than or equal to a band gap of at least one second conversion cell of the plural second photoelectric conversion cells, the one or more second photoelectric conversion cells are gallium arsenide (GaAs)-based photovoltaic cells, and the second junction layer is a gallium phosphide arsenide (GaPAs) layer.