Conductive Paste Solar Cell Electrodes Composite Glass Frit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conductive pastes for solar cell front surface electrodes face challenges in achieving both low contact resistance and high tensile strength, with existing glass frit compositions failing to simultaneously provide these properties effectively.
Innovation Solution
A conductive paste comprising a mixture of tellurium-based glass frit containing tellurium, tungsten, and bismuth, and a lead-bismuth-based glass frit that does not exceed 1,000 ppm tellurium, used in conjunction with a conductive powder and organic vehicle, is applied to form the front surface electrode, allowing for a low contact resistance and high tensile strength through a specific blending ratio and firing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If lead-containing glass frit is used, then tensile strength is improved, but contact resistance increases
Solution Approach 1:
The patent uses a composite glass frit system combining lead-containing glass frit (providing tensile strength through PbO content of 30-70 wt%) with tellurium-containing glass frit (providing low contact resistance through TeO2 content of 20-50 wt%). This composite approach allows simultaneous achievement of high tensile strength and low contact resistance by integrating the complementary properties of different glass materials.
Solution Approach 2:
The patent optimizes specific compositional parameters including PbO content (30-70 wt%), TeO2 content (20-50 wt%), and Bi2O3 content (5-20 wt%) to achieve the desired balance between tensile strength and contact resistance. By precisely controlling these chemical composition parameters, the glass frit exhibits both high mechanical strength and low electrical contact resistance.
2Reliability
If tellurium-containing glass frit is used, then contact resistance is reduced, but tensile strength becomes insufficient
Solution Approach 1:
The patent combines tellurium-containing glass frit (which provides low contact resistance) with lead-containing glass frit (which provides high tensile strength). The synergistic combination allows the glass frit to exhibit both low contact resistance from the tellurium component and high tensile strength from the lead component, overcoming the limitations of using either material alone.
Solution Approach 2:
The patent adjusts the compositional parameters by incorporating PbO (30-70 wt%) to enhance tensile strength while maintaining TeO2 (20-50 wt%) for low contact resistance. This parameter optimization ensures that the glass frit achieves both low contact resistance and high tensile strength simultaneously.
3Adaptability or versatility
If glass frit containing both lead and tellurium is used, then properties are intermediate, but both tensile strength and contact resistance remain inadequate
Solution Approach 1:
Rather than using a single glass frit with intermediate properties containing both lead and tellurium, the patent employs a composite system of two distinct glass frits: lead-containing glass frit (providing high tensile strength) and tellurium-containing glass frit (providing low contact resistance). This approach allows each component to contribute its optimal property without the compromises inherent in intermediate compositions.
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 results in solar cell elements with front surface electrodes exhibiting low contact resistance and high tensile strength, thereby enhancing the conversion efficiency of the solar cell.
Implementation Method 1
the antireflective film is ordinarily dissolved and removed by the action of the glass frit present in the conductive paste
Implementation Method 2
the mixed glass frit contains, in the form of mixture, a tellurium-based glass frit containing tellurium, tungsten, and bismuth and a lead-bismuth-based glass frit
Data Source
Figure 1
Figure 2(a)~2(e)
AI summary
The purpose of the present invention is to provide: a conductive paste for forming a solar cell element front surface electrode that has a lower contact resistance and a high tensile strength; and a method for manufacturing the same. A conductive paste for a solar cell element front surface electrode that is used to form a front surface electrode of a solar cell element that is provided with a semiconductor substrate, an antireflective film disposed in a first region on one main surface of the semiconductor substrate, and a front surface electrode disposed in a second region on the one main surface of the semiconductor substrate. The conductive paste is characterized by comprising a conductive powder, a mixed glass frit, and an organic vehicle in which the mixed glass frit contains, in the form of mixture, a tellurium-based glass frit containing tellurium, tungsten, and bismuth as essential components and a lead-bismuth-based glass frit that contains lead and bismuth as essential components and that substantially does not contain tellurium.