TOPCon Solar Cell Contacts That Limit Passivation Damage
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Solution Overview
Problem
Traditional tunnel oxide passivated contact (TOPCon) solar cells experience damage and recombination issues with the passivation and antireflection layers due to etching or laser ablation processes, which hinder performance improvement and photoelectric conversion efficiency.
Innovation Solution
A solar cell design featuring connection holes in the passivation and antireflection layers with finger electrodes that are smaller than the electrodes themselves, allowing for electrical connection without extensive damage, and a manufacturing method involving sintering to create these connections, reducing damage to the passivation structure while ensuring good electrical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If etching or laser ablation is used to expose doped polysilicon for electrode manufacturing, then electrical contact is achieved, but damage and recombination increase in the passivation layer and antireflection layer
Solution Approach 1:
Instead of removing material (etching/laser ablation) to create contact holes, the patent inverts the approach by forming contact holes through deposition and sintering processes. The metal finger pattern is printed and sintered to directly form conductive pathways through the passivation layer without requiring aggressive removal processes, thereby preserving the integrity of the passivation and antireflection layers while achieving electrical contact.
2Ease of manufacture
If traditional etching processes are used to create connection holes, then electrodes can contact the doped polysilicon layer, but the passivation structure suffers damage and recombination
Solution Approach 1:
The patent replaces the mechanical/chemical removal process (etching) with a thermal deposition and sintering process. Metal slurry is printed onto the surface and sintered to form conductive fingers that penetrate through the passivation layer to contact the doped polysilicon. This substitution eliminates the need for aggressive etching chemistry that damages the passivation structure, reducing recombination losses while maintaining manufacturing feasibility.
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
The solution minimizes damage and recombination in the passivation structure, leading to higher photoelectric conversion efficiency compared to traditional solar cells.
Implementation Method 1
a manufacturing method involving sintering to form electrodes without etching or laser ablation
Data Source
AI summary
A solar cell and a manufacturing method thereof, and a photovoltaic system. The solar cell includes: a substrate layer including a first surface and a second surface arranged oppositely along a thickness direction thereof; a tunnel oxide layer, a first doped polysilicon layer, and a first passivation layer sequentially arranged on the first surface of the substrate layer in a direction gradually away from the substrate layer; and a first finger electrode layer, at least one of the first fingers being arranged in first connection holes, bottoms of the first connection holes being located in the first doped polysilicon layer, and the first fingers passing through the first connection holes corresponding thereto to be electrically connected to the first doped polysilicon layer; and in the first direction, widths of the first connection holes being all less than widths of the first fingers corresponding to the first connection holes. While ensuring good electrical connection, the solar cell causes less damage and recombination to a passivation structure of the solar cell, and has high photoelectric conversion efficiency.