Double-back-contact three-terminal laminated solar cell

Abstract

The invention relates to the field of solar cells, and particularly provides a double-back-contact three-terminal laminated solar cell. The cell is formed by vertically stacking a wide-band-gap sub-cell and a narrow-band-gap sub-cell in the light incidence direction, and three-end electrical connection is achieved through a back contact electrode. The innovativeness is as follows: the wide-band-gap sub-cell and the narrow-band-gap sub-cell are arranged to be of a back contact structure, so that light shielding loss and parasitic absorption loss are avoided; a micro-nano light trapping structure electrode is adopted to form a double light trapping array, and light absorption is enhanced. Finite element simulation shows that the conversion efficiency of the structure under AM1.5 G standard illumination reaches 32.5%, and compared with a traditional back contact three-terminal structure, the absolute efficiency is improved by 2.6%; the short-circuit current density of the wide-band gap sub-battery is improved by 8%, and the short-circuit current density of the narrow-band gap sub-battery is improved by 13%; and the external quantum efficiency is obviously improved within the range of 300-1000nm.

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