TOPCon Solar Cell Front Contact Patterning With Laser Oxidation
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Solution Overview
Problem
The front-side structure of N-type Tunnel Oxide Passivated Contact (TOPCon) solar cells affects efficiency, with issues such as high contact resistance and interface defect states at metal/semiconductor contacts, limiting the cell's performance.
Innovation Solution
A method involving laser processing to form a patterned polysilicon contact layer and silicon oxide mask layer, followed by selective metal electrode formation, optimizing the front-side structure to reduce contact resistance and improve passivation quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal electrode is directly formed on the semiconductor base, then the electrical contact is established, but the contact resistance is high and interface defect states increase
Solution Approach 1:
The patent introduces a polysilicon contact layer as an intermediary between the metal electrode and the semiconductor base. This intermediate layer serves as a mediator that reduces interface defect states and lowers contact resistance, resolving the contradiction between establishing electrical contact and maintaining low contact resistance. The polysilicon layer acts as a buffer that improves the quality of the metal-semiconductor interface.
2Ease of manufacture
If the front-side structure is simplified for easier manufacturing, then the manufacturing process is easier, but the photoelectric conversion efficiency is reduced
Solution Approach 1:
The patent applies local quality by implementing the polysilicon contact layer specifically at the metal electrode-semiconductor base interface where it is most needed, rather than uniformly across the entire structure. This localized approach improves contact quality and efficiency at critical points while maintaining manufacturing simplicity in other areas, thus resolving the contradiction between ease of manufacture and photoelectric conversion efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances the efficiency of TOPCon solar cells by reducing recombination currents and increasing open circuit voltage and short circuit current, achieving mass production efficiencies beyond 26%.
Implementation Method 1
The amorphous silicon layer is annealed to form a first polysilicon contact layer
Implementation Method 2
The first polysilicon contact layer is laser oxidized to pattern the first polysilicon contact layer and to oxidize a portion of a thickness of the first polysilicon contact layer, to form a patterned silicon oxide mask layer
Data Source
AI summary
A solar cell structure, a method for manufacturing a solar cell structure, and a solar cell are provided. The method includes: forming a precursor structure on a surface of a base, the precursor structure including a first tunnel layer covering the base surface, and an amorphous silicon layer covering a surface of the first tunnel layer; annealing the amorphous silicon layer to form a first polysilicon contact layer; laser oxidizing the first polysilicon contact layer to pattern it and to oxidize a portion of a thickness of the first polysilicon contact layer to form a patterned silicon oxide mask layer; removing the amorphous silicon layer and/or the first polysilicon contact layer in a region not covered by the patterned silicon oxide mask layer; removing the silicon oxide mask layer; and forming a first metal electrode on a surface of a remaining portion of the first polysilicon contact layer.