Silicon Wafer Passivation During Cutting, Degluing, and Cleaning
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Solution Overview
Problem
Existing silicon wafers used in solar cells suffer from limited conversion efficiency due to mechanical damage during cutting and inadequate passivation processes, which increase production costs and reduce storage stability.
Innovation Solution
A method involving the use of non-metallic compounds bonded with silicon ions via single bonds in treatment solutions for cutting, degluing, and cleaning processes to form a passivation layer, reducing surface damage and impurity residues, and enhancing texturing uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cutting methods are used for silicon ingot, then production efficiency is maintained, but mechanical damage occurs on the silicon wafer surface reducing conversion efficiency
Solution Approach 1:
The patent introduces a liquid crystal composition as an intermediary substance during the cutting process. This composition is applied to the silicon ingot surface before cutting and acts as a mediator that reduces mechanical damage. The liquid crystal composition contains specific compounds (such as fluorinated compounds or compounds with silicon-bonding capability) that protect the silicon surface during cutting while maintaining production efficiency, thereby resolving the contradiction between surface quality and production efficiency.
Solution Approach 2:
The patent applies the liquid crystal composition to the silicon ingot surface before the cutting process begins. This preliminary action prepares the surface in advance to resist mechanical damage during cutting. By pre-treating the surface with the protective composition, the method prevents damage before it occurs rather than attempting to repair it afterward, thus maintaining both high surface quality and production efficiency.
2Manufacturing precision
If existing passivation processes are used, then production costs increase, but conversion efficiency improvement is limited
Solution Approach 1:
The patent develops a liquid crystal composition that serves multiple functions: it acts as a cutting protective layer, a passivation agent, and a texturing promoter simultaneously. This multi-functional composition eliminates the need for separate passivation process steps, thereby reducing production costs while achieving uniform texturing and improved conversion efficiency. The single composition performs what previously required multiple separate processes.
Solution Approach 2:
The patent modifies the chemical composition parameters of the treatment solution by incorporating specific compounds (such as fluorinated compounds with specific molecular structures or compounds containing silicon-bonding groups) at optimized concentrations. These parameter changes enable the solution to achieve both passivation and texturing functions, improving texturing uniformity while maintaining cost-effectiveness through a simplified process.
3Manufacturing precision
If conventional cleaning processes are used, then impurity residues remain on the surface, but additional passivation treatment increases complexity
Solution Approach 1:
The patent merges the cleaning function and passivation function into a single liquid crystal composition application step. The composition contains compounds that simultaneously remove impurity residues from the silicon surface and form a protective passivation layer. This merging of functions eliminates the need for separate cleaning and passivation treatment steps, achieving high surface cleanliness without increasing process complexity.
Solution Approach 2:
The liquid crystal composition acts as an intermediary that performs both cleaning and passivation. The composition's chemical structure enables it to interact with and remove impurities while simultaneously forming a protective layer on the silicon surface. This dual-action intermediary substance simplifies the overall process while achieving the desired surface cleanliness and passivation.
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
This approach improves the minority carrier lifetime, specific surface area, and fill factor of silicon wafers, leading to increased conversion efficiency of solar cells while simplifying the production process and reducing costs.
Implementation Method 1
at least one of the first treatment solution, the second treatment solution and the third treatment solution includes a non-metallic compound that is bonded with a silicon ion via a single bond
Implementation Method 2
the conversion efficiency of existing solar cells fabricated from silicon wafers is limited... the present application relates to a silicon wafer, a preparation method of the silicon wafer, and a passivation treatment solution, which can improve the texturing uniformity of the silicon wafer and further improve the conversion efficiency of a solar cell using the silicon wafer
Data Source
AI summary
A silicon wafer, a preparation method of the silicon wafer, and a passivation treatment solution is disclosed. The preparation method of the silicon wafer can include the following steps: providing a solar silicon ingot; cutting the solar silicon ingot with a first treatment solution to form a pretreated silicon wafer; degluing the pretreated silicon wafer with a second treatment solution to obtain a deglued silicon wafer; and cleaning the deglued silicon wafer with a third treatment solution to obtain the silicon wafer; wherein at least one of the first treatment solution, the second treatment solution and the third treatment solution comprises a non-metallic compound that is bonded with a silicon ion via a single bond.