TOPCon solar cell and manufacturing method thereof

Abstract

The invention provides a TOPCon solar cell and a manufacturing method thereof. The manufacturing method comprises the following steps: (a) providing an N-type silicon wafer for a TOPCon solar cell; (b) texturing the silicon wafer and diffusing on the first surface of the silicon wafer to form a PN junction; (c) sequentially forming a silicon oxide layer, a microcrystalline silicon seed crystal layer, a doped amorphous silicon layer or a doped microcrystalline silicon layer on a second surface, opposite to the first surface, of the silicon wafer; (d) carrying out crystallization annealing treatment on the silicon wafer to crystallize microcrystalline silicon and / or amorphous silicon into polycrystalline silicon; (e) respectively forming a first anti-reflection passivation film and a secondanti-reflection passivation film on the first surface and the second surface of the silicon wafer; and (f) respectively forming a first electrode and a second electrode on the first surface and the second surface of the silicon wafer. According to the invention, the problem of film explosion when the doped amorphous silicon layer or the doped microcrystalline silicon layer reaches a certain thickness can be effectively solved, the leakage current can be effectively reduced, and improvement of the open-circuit voltage, the filling factor and the conversion efficiency of the TOPCon cell can be facilitated.

Description

technical field [0001] The invention relates to the field of solar cell manufacturing, in particular to a TOPCon solar cell and a manufacturing method thereof. Background technique [0002] The concept of TOPCon solar cells was first proposed by Fraunhofer ISE at the 28th EU PVSEC in 2013, which uses an ultra-thin silicon oxide layer and doped amorphous silicon to passivate the back of the cell. This structure provides a good surface passivation for the back of the battery. The ultra-thin silicon oxide layer can allow many electrons to tunnel into the polysilicon layer, while blocking the recombination of minority electrons and holes, and then the electrons are transported laterally in the polysilicon layer and collected by the metal, thereby It greatly reduces the metal contact recombination current and improves the open circuit voltage and short circuit current of the battery. [0003] In the prior art, some practitioners use furnace-tube low pressure chemical vapor depos...

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Problems solved by technology

[0004] The above-mentioned process of forming the passivation layer on the back of the TOPCon cell by furnace tube type LPCVD has the following problems: first, the temperature for depositing silicon oxide layer and amorphous silicon is too high; second, additional ion implantation equipment needs to be purchased, which increases the The complexity of the process; third, the doping of amorphous silicon by ion implantation has problems of uniformity and concentric circles; fourth, the quartz tube of the tube furnace is expensive, which is a consumable and needs to be replaced frequently

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