Silicon-Lead-Lithium Oxide Frit for Water-Resistant Solar Cell Paste
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Solution Overview
Problem
Existing conductive pastes for solar cells are prone to corrosion from water vapor, leading to reduced bonding force and conductivity between the conductive electrode and the silicon wafer, resulting in decreased or complete failure of photoelectric conversion efficiency.
Innovation Solution
A silicon-lead-lithium oxide frit system is introduced, comprising specific ratios of SiO2, PbO, Li2O, B2O3, Al2O3, and Bi2O3, which forms a conductive paste with improved water resistance and maintained or enhanced photoelectric conversion efficiency when used in solar cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive paste with silicon oxide and alkali metal oxide is used, then initial conductivity and adhesion are achieved, but water vapor corrosion reduces bonding force and conductivity over time
Solution Approach 1:
The patent changes the chemical composition parameters of the oxide frit by replacing traditional alkali metal oxides (Na2O, K2O) with lithium oxide (Li2O) and adjusting the SiO2:PbO:Li2O ratio. This parameter change makes the oxide frit less susceptible to water vapor corrosion while maintaining initial conductivity and adhesion properties.
Solution Approach 2:
The patent creates a composite oxide frit system combining SiO2, PbO, and Li2O in specific ratios, forming a new material composition that resists water vapor corrosion. The composite structure leverages the complementary properties of each oxide component to achieve both initial performance and long-term stability.
2Strength
If oxide frit is added to conductive paste to improve adhesion, then bonding force increases, but water vapor causes oxide corrosion and reduces conductivity
Solution Approach 1:
The patent modifies the oxide composition parameters by using Li2O instead of traditional alkali metal oxides and optimizing the SiO2:PbO:Li2O ratio. This parameter change ensures the oxide frit maintains strong bonding force while resisting water vapor corrosion to preserve conductivity stability over time.
3Ease of manufacture
If traditional alkali metal oxide is used in conductive paste, then initial adhesion is achieved, but H+ replacement reaction occurs with water vapor leading to network structure changes
Solution Approach 1:
The patent changes the alkali metal component from traditional Na2O or K2O to Li2O and adjusts the overall composition ratios. This parameter change prevents the H+ replacement reaction that occurs with traditional alkali metals, thereby maintaining the oxide network structure stability while still achieving initial adhesion.
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 silicon-lead-lithium oxide frit system significantly enhances water resistance and maintains or improves the photoelectric conversion efficiency of solar cells by reducing corrosion effects, thereby preventing failures due to water vapor exposure.
Implementation Method 1
The water vapor has a corrosion effect on the oxide in the conductive electrode mixture on the surface of the solar cell. When the oxide is corroded by the water vapor, the bonding force and the conductivity between the conductive electrode of the cell and the silicon wafer are reduced
Data Source
AI summary
The present disclosure discloses a silicon-lithium-lead system, a conductive paste and a preparation method thereof, and belongs to the field of solar cells. A silicon-lead-lithium oxide frit includes the following composition: Sia—Pbb—Lic—(Bx—Aly—Biz)-Me-Of, where, 0<a<0.6, 0<b<0.8, 0<c<0.6, x+y+z=d, the x and the y are not zero at the same time, and the z is greater than zero. In the present disclosure, by adding B2O3 and Bi2O3, Al2O3 and Bi2O3, or B2O3, Al2O3 and Bi2O3 at the same time, the prepared frit has greater water resistance, and therefore, a solar cell prepared by using the conductive paste containing glass has good water resistance. In addition, the photoelectric conversion efficiency of the solar cell prepared by using the conductive paste prepared in the present disclosure can also be maintained, or even be slightly improved.