Solar Cell Edge Space Formation Using Segmented Laser Ablation
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Solution Overview
Problem
The formation of edge spaces in CIS-based thin film solar cell modules using sandblasters or lasers can damage the laminated films, leading to reduced conversion efficiency and increased production costs, as the strong lasers required to remove the first electrode can also melt the CIS or second electrodes, causing shunts in the division grooves.
Innovation Solution
A method involving the formation of first and second edge spaces with specific widths, where the second edge space is larger than the first, using either a weak laser or mechanical scribing to remove the second layers and a strong laser to remove the first electrode, ensuring the second layers are not damaged, and masking the second layers during sandblasting to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a strong laser is used to remove the first electrode to form an edge space, then the first electrode can be effectively removed, but the CIS or second electrodes can be melted causing shunts in the division grooves and deteriorating conversion efficiency
Solution Approach 1:
The edge space formation process is segmented into multiple stages: first forming a preliminary edge space by removing the first electrode, then forming a second edge space by removing the second electrode and CIS layer. This segmentation allows different laser powers to be used for different removal tasks, preventing damage to sensitive layers.
Solution Approach 2:
The first electrode is removed in advance to create a preliminary edge space before removing the second electrode and CIS layer. This preliminary action protects the CIS layer from direct exposure to the strong laser power needed for first electrode removal.
2Ease of manufacture
If sandblasting is used to remove the laminated film to form an edge space, then the edge space can be formed, but the laminated film can be damaged leading to reduced conversion efficiency
Solution Approach 1:
The first electrode is removed in advance by sandblasting to create a preliminary edge space, establishing a protective boundary before subsequent laser processing removes the second electrode and CIS layer.
3Ease of manufacture
If the edge space is formed by removing the laminated film, then the frame can be omitted reducing production cost and weight, but the solar cell circuit performance can be deteriorated
Solution Approach 1:
The edge space formation is segmented into multiple removal stages targeting different layers sequentially, allowing precise control over which materials are removed and which are preserved to maintain circuit performance.
Solution Approach 2:
Different removal methods and parameters are applied to different layers: sandblasting for the first electrode, then laser processing with controlled power for the second electrode and CIS layer. This local quality approach ensures each layer is removed appropriately without damaging others.
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 prevents the deterioration of solar cell conversion efficiency and simplifies the manufacturing process by minimizing the risk of shunts and reducing production costs, as demonstrated by improved conversion efficiency and fill factor ratios compared to conventional methods.
Implementation Method 1
a step of forming a first edge space having a first width by removing the first layer (408) and the second layer (404, 405, 406) by the first width from an end part of the glass substrate (409)
Implementation Method 2
using either a weak laser or mechanical scribing to remove the second layers
Implementation Method 3
a frameless solar cell module that has an edge space (a space where device layers are not piled) provided in a periphery of a solar cell circuit is also proposed
Data Source
AI summary
The solar cell module having a preferable edge space that prevents characteristics of a solar cell such as conversion efficiency from being deteriorated without making processes complicated is provided. In a method for manufacturing a solar cell module including a substrate glass, a first layer formed on the substrate glass and a second layer formed on the first layer, the method includes a step of forming a first edge space having a first width by removing the first layer and the second layer by the first width from an end part of the glass substrate and a step of forming a second edge space by removing only the second layer by a second width from the end part of the glass substrate, and the width of the second edge space is larger than the width of the first edge space.