Back-Surface Electrode Penetrating Passivation Layer for Solar Cell Edge Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solar cell elements with a PERC structure face issues with peeling at the peripheral edge due to temperature-induced expansion and contraction, leading to deterioration of electric characteristics, as the protective layer and electrode tend to peel off from the silicon substrate.
Innovation Solution
A solar cell element design featuring a back-surface electrode that penetrates the passivation layer and surrounds the peripheral edge, reducing temperature-induced stress and improving adhesion, along with a manufacturing method that includes forming a passivation layer and electrode structure to enhance durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer and electrode are positioned on the passivation layer of a PERC solar cell, then photoelectric conversion efficiency is improved, but peeling occurs at the peripheral edge due to temperature-induced expansion and contraction
Solution Approach 1:
The electrode is divided into two distinct parts: a linear electrode part positioned along the peripheral edge that penetrates the passivation layer, and a plate-like electrode part positioned on the passivation layer. This segmentation allows each part to handle different stress conditions - the linear part anchors at the edge where thermal stress is highest, while the plate-like part collects current from the bulk, thereby preventing peeling caused by temperature-induced expansion and contraction.
Solution Approach 2:
The linear electrode part extends in the thickness direction by penetrating the passivation layer, adding a vertical dimension to the electrode structure. This dimensional change enables the electrode to anchor through the passivation layer and establish electrical connection with the semiconductor substrate, creating a more robust mechanical and electrical connection that resists thermal stress.
2Reliability
If the electrode penetrates the passivation layer to connect with the semiconductor substrate, then electrical connection is improved, but manufacturing complexity increases
Solution Approach 1:
The electrode is segmented into a linear electrode part for penetration and electrical connection, and a plate-like electrode part for current collection. This segmentation simplifies the design by assigning specific functions to each part - the linear part handles the complex penetration and connection task, while the plate-like part provides a simple current collection surface, making the overall structure manageable despite the penetration requirement.
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 effectively reduces peeling and maintains electrical characteristics, enhancing the long-term reliability of solar cell elements by minimizing stress and improving adhesion between the electrode and substrate.
Implementation Method 1
a passivation layer 4, a protective layer 11 for protecting this passivation layer 4, and an electrode 8 positioned on this protective layer 11
Implementation Method 2
As a crystalline silicon based solar cell element with high photoelectric conversion efficiency
Data Source
AI summary
A solar cell element is provided with a semiconductor substrate, a passivation layer, and an electrode. The semiconductor substrate has a first surface and a second surface that is positioned on a back side of the first surface. The passivation layer is positioned on the second surface of the semiconductor substrate. The electrode is positioned on the passivation layer and positioned in the state of being electrically connected to the semiconductor substrate. The electrode includes a linear electrode part that is positioned along a peripheral edge of the semiconductor substrate when the semiconductor substrate is seen from the second surface side in plane perspective view, and is positioned in the state of penetrating the passivation layer in a thickness direction.