Solar Cell Conductive Paste to Limit Glass Fire-Through
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Solution Overview
Problem
The existing conductive pastes for solar cells often result in reduced efficiency due to excessive glass fire-through during the sintering process, which affects the electrical connection and performance of the solar cells.
Innovation Solution
A conductive paste containing a high-melting point tellurium alloy compound, such as lead telluride, zinc telluride, or silver telluride, with a melting point of 900°C or more, is used to inhibit glass fire-through, improving electrical connection and cell efficiency by controlling the degree of fire-through.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional conductive paste is used with standard sintering process, then the sintering can be completed efficiently, but excessive glass fire-through occurs which reduces cell efficiency
Solution Approach 1:
The patent introduces a tellurium alloy compound with a high melting point (900°C or higher) that is at least 300°C higher than the softening point of the glass. This parameter change in melting point creates a temperature window that allows the sintering process to complete while preventing the glass from firing through excessively, thus resolving the contradiction between sintering efficiency and cell efficiency
Solution Approach 2:
The tellurium alloy compound acts as an intermediary substance between the silver powder and the glass. It controls the interaction between these components during sintering, allowing the silver to bond properly while restraining the glass from firing through the PN junction, thereby maintaining both processability and device performance
2Ease of manufacture
If glass fire-through is allowed to proceed excessively, then the sintering process is simplified, but electrical connection deteriorates and cell efficiency decreases
Solution Approach 1:
By changing the melting point parameter of the added compound to be significantly higher than the glass softening point, the patent creates a controlled temperature gradient during sintering. This allows the glass to soften sufficiently for bonding while automatically limiting fire-through, providing self-control without complex process parameters
Solution Approach 2:
The patent converts the potentially harmful effect of glass fire-through into a beneficial self-limiting process. The tellurium alloy compound enables controlled fire-through that improves electrical connection while the high melting point automatically prevents excessive fire-through, turning what was previously a manufacturing defect into a controlled feature
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 use of high-melting point tellurium alloy compounds in the conductive paste effectively prevents excessive glass fire-through, enhancing the electrical connection and increasing the conversion efficiency of solar cells.
Implementation Method 1
the tellurium alloy compound has a melting point at least 300 °C higher than the softening point of the glass; and wherein the melting point of the tellurium alloy compound is 900°C or more
Data Source
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AI summary
A conductive paste for a solar cell, a solar cell and a manufacturing method thereof, and a solar cell module are provided. The conductive paste for a solar cell includes a silver powder, a glass, an organic vehicle, and a tellurium alloy compound, wherein the tellurium alloy compound has a melting point at least 300°C higher than the softening point of the glass.