Back junction backcontact solar cell

Abstract

The invention provides a back junction backcontact solar cell. The back junction backcontact solar cell comprises a substrate, a composite layer, a tunneling oxide layer, a P-type doped semiconductor layer, an N-type doped semiconductor layer, a positive electrode and a negative electrode, wherein the composite layer is combined on a front surface of the substrate, the tunneling oxide layer is combined on a back surface of the substrate, the P-type doped semiconductor layer and the N-type doped semiconductor layer are combined on the tunneling oxide layer, the positive electrode is arranged on the P-type doped semiconductor layer, and a negative electrode is arranged on the N-type doped semiconductor layer. The invention proposes a back junction backcontact solar cell employing a tunneling oxide layer passivation contact structure; with the adoption of the tunneling oxide layer passivation contact structure, direct contact of a metal electrode and the substrate is prevented, the combination of a carrier on a metal contact interface is effectively reduced, and an opening voltage of the cell is increased; and moreover, combination addition cannot brought by metal contact, the vast majority of areas of an emission field and a back field can be covered by metal contact, transverse transmission of the carrier is prevented, the series resistance is favorably reduced, and the cell efficiency is further improved.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and relates to a back-junction and back-contact solar cell, in particular to a back-junction and back-contact solar cell with a tunnel oxide layer passivation contact structure on the back. Background technique [0002] A solar cell, also known as a "solar chip" or a "photovoltaic cell", is a photoelectric semiconductor sheet that uses sunlight to directly generate electricity. It is a device that directly converts light energy into electrical energy through the photoelectric effect or photochemical effect. As long as the solar cell is illuminated by light that meets a certain illuminance condition, it can output voltage instantly and generate current when there is a loop. In physics, it is called solar photovoltaic (Photovoltaic, abbreviated as PV), or photovoltaic for short. The working principle of a solar cell is that when sunlight shines on the p-n junction of a semiconductor, new hole-...

AI Technical Summary

Problems solved by technology

However, a problem that most solar cells, including back-junction and back-contact solar cells, have not solved is that after the metal and the substrate form an ohmic contact, a large number of interface states will be introduced on the contact surface, which makes the carrier on the surface The recombination rate increases significantly, which can greatly reduce the performance of the battery

The usual solution is to minimize the contact area between the metal and the substrate, but this will cause the lateral transport of carriers, increase the series resistance, and reduce the performance of the battery.

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