PURPOSE: To obtain a DC power source having a relatively high voltage, by providing a plurality of solar cells at the outside periphery of a heat-transmitting medium pipe in a series-connected condition.
CONSTITUTION: A plurality of the solar cells 4 are placed in the series-connected condition around the outside periphery of the heat-transmitting medium pipe 3 placed in a vacuum heat-insulating layer 2 inside a light-transmitting glass pipe 1. Film pieces of a metal to become substrates 5 having a predetermined width are vapor-deposited on the outside periphery of the pipe 3 (having an electrically insulating property) at regular intervals in the axial direction of the pipe 3, and amorphous semiconductors 6 having a predetermined width are provided on the substrates 5 at regular intervals in the axial direction of the pipe 3 so that each of the semiconductors 6 bridges an adjacent pair of the substrates 5. Further, transparent electrodes 7 such as ITO having predetermined dimensions are provided at regular intervals in the axial direction of the pipe 3 so as to cover both outside peripheries of the semiconductors 6 and parts of the substrates 5 exposed at each gap between the adjacent pair of the semiconductors 6, thereby constituting the solar cell 4.
NISHIO MICHIO
WATANABE YASUMASA
FUJI ELECTRIC CO LTD