Open Fabric Conductor for Photovoltaic Cells

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Solution Overview

Problem

Conventional solar cells face inefficiencies due to shading from increasing conductor track arrangements, which reduce power yield and require additional effort for establishing good electrical contact, making them less cost-effective and less efficient.

Innovation Solution

An open fabric with fusible threads is applied directly to the photoelectrically active surface element, where heat treatment melts the threads to form a firm connection, eliminating the need for a continuous substrate coating and enhancing light transmission and electrical contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a continuous coating substrate is used to form the conductor track arrangement, then good electrical contact is achieved, but light transmission is reduced and the structure becomes more complex

Engineering Contradiction:
Improveelectrical contact qualityVSAvoidlight transmission
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The continuous coating substrate is replaced by a fabric with an open structure consisting of discrete threads. This segmentation allows light to pass through the gaps between threads while maintaining electrical conductivity through the conductive threads that contact the semiconductor substrate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fabric uses a combination of conductive and non-conductive threads in a specific pattern. Only the conductive threads make contact with the semiconductor substrate to provide electrical connection, while the non-conductive threads provide structural support without blocking light, creating local functional differentiation.

Inventive Principle:
Principle #3Local quality

2Device complexity

If the conductor track arrangement is applied directly on the photoelectrically active surface, then shading increases and power yield reduces, but the structure simplifies

Engineering Contradiction:
Improvestructure simplicityVSAvoidpower yield
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The fabric employs an open porous structure with significant void space between threads. This allows a large portion of incident light to pass through to the photoelectrically active surface, reducing shading effects while maintaining the simplified direct-application structure.

Inventive Principle:
Principle #31Porous materials

3Reliability

If additional adhesive layers or soldering paste are used to fix the fabric, then good electrical contact is achieved, but the manufacturing process becomes more complex and costly

Engineering Contradiction:
Improveelectrical contact qualityVSAvoidmanufacturing process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The additional adhesive layers and soldering paste from conventional processes are completely removed. The fabric threads themselves are designed to provide both mechanical attachment and electrical contact functions, eliminating the need for separate contact-establishment steps.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The fabric threads serve multiple functions simultaneously: they provide mechanical support as a substrate, establish electrical contact with the semiconductor, and maintain the open structure for light transmission. This multi-functionality eliminates the need for separate components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Strength

If high heat treatment is applied to melt the threads for firm connection, then mechanical robustness improves, but thermal damage to thermally sensitive materials increases

Engineering Contradiction:
Improvemechanical robustnessVSAvoidthermal damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The melting temperature of the fabric threads is specifically adjusted to be below the damage threshold of thermally sensitive semiconductor materials. This parameter change allows the threads to melt and bond to the substrate at temperatures that provide mechanical robustness without causing thermal damage.

Inventive Principle:
Principle #35Parameter changes

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 method improves the efficiency and cost-effectiveness of solar cells by reducing internal resistance and thermal damage, while maintaining good light transmission and mechanical robustness, making them suitable for thermally sensitive materials like silicon heterostructure solar cells.

Implementation Method 1

a heat treatment takes place in which the fusible threads are at least partially melted, the open fabric with the melted threads being firmly attached to the surface element is connected

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

a heat treatment takes place in which the fusible threads are at least partially melted

Methodology Applied
Scientific EffectThermal energy: Heating

Implementation Method 3

Light impinging on the planar element generates free charge carriers in the planar element constructed in layers. By appropriately directing the free charge carriers generated in this way, a voltage can be generated which can be used to generate electricity

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3410494B1Photovoltaic cell and modules and method for their preparation
Publication Date: 2019.10.09 SEFAR AG
  • EP3410494B1 patent drawingFigure 1
  • EP3410494B1 patent drawingFigure 2~4
  • EP3410494B1 patent drawingFigure 5~6

AI summary

The invention relates to a photovoltaic cell and a method for its manufacture, comprising a photoelectrically active surface element and at least one conductor arrangement on at least one surface side of the surface element. According to the invention, an open fabric is applied to the at least one surface side of the photoelectrically active surface element to form the conductor arrangement. This open fabric is woven from electrically conductive threads and transparent, electrically non-conductive threads, and is free of any planar coating.