Back contact solar cell

Abstract

A back contact solar cell includes a solar cell substrate, an intrinsic layer, a second conductive type semiconductor layer and an electrode layer. The solar cell substrate includes a substrate body doped with a first conductive type semiconductor and a plurality of first conductive type semiconductor doped regions. The first conductive type semiconductor doped region is formed on a back side of the substrate body. The intrinsic layer is formed on the back side, and includes a plurality of first openings to expose the first conductive type semiconductor doped regions. The second conductive type semiconductor layer is deposited on the intrinsic layer, and includes a plurality of second openings correspond the first openings. The electrode layer includes a plurality of first electrode regions and a second electrode region. The first electrode regions are disposed on the first conductive type semiconductor doped regions. The second electrode regions are disposed on the second conductive type semiconductor layer, and separated with the first electrode regions.

Description

technical field [0001] The invention relates to a back-contact solar cell, in particular to a back-contact solar cell in which an intrinsic layer and a second-type semiconductor layer are deposited on a semiconductor substrate body doped with a first-type semiconductor material. Background technique [0002] Under the premise of the oil crisis and the greenhouse effect, solar energy is the least polluting and sustainable energy source, so the development of solar cells has flourished. Generally speaking, the structure of a solar cell is mainly to dope a P-type semiconductor and an N-type semiconductor in a silicon wafer to form a PN junction, and when the solar cell is irradiated by light to generate electron-hole pairs, the electron-hole pair generated by the PN junction is used. A built-in electric field separates the electrons from the holes, and then the electrons and holes are guided out through the circuit formed by the electrodes. [0003] However, since the existing...

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Problems solved by technology

[0005] However, in the back contact solar cell, in order to further reduce the recombination of electron holes at the P-N junction, reduce the surface recombination rate and increase the open circuit voltage, etc., there have been previous reports disclosing a back contact with a heterojunction type solar cell, such as Taiwan Patent Publication No. 201322465 patent document, which discloses that a solar cell PA200 has a second conductivity type doped region PA112, and the second conductivity type doped region PA112 is located below the second conductivity type semiconductor layer PA110 In the first conductive type silicon substrate PA102, the surface of the first conductive type silicon substrate PA102 has an intrinsic semiconductor layer PA106, and the second conductive type semiconductor layer PA110 is located on the intrinsic semiconductor layer PA106. Doping the second conductivity type doped region PA112 in the substrate PA102 directly forms a heterojunction; among them, since the intrinsic semiconductor layer PA106 in the previous proposal is an amorphous semiconductor layer, its resistance is still higher than that of metal, and acts as a back electric field (Back Surface Field, BSF) the first conductivity type semiconductor layer PA108 is arranged on the intrinsic semiconductor layer PA106, so its ability to suppress surface recombination is relatively poor; in addition, due to the first conductivity type silicon substrate PA102 and the second conductivity type The doped region PA112 is in direct contact, resulting in too many defects, which will lead to poor efficiency of solar cells

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