Wavy Monolithic Interconnects for Thin-Film PV Sheet Resistance

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Solution Overview

Problem

Thin-film photovoltaic devices face challenges with high resistivity in transparent front-contact layers, requiring additional grid structures that increase production costs, reduce efficiency, and introduce points of failure due to strain from encapsulation materials, while also limiting design flexibility and aesthetic appeal.

Innovation Solution

The design and manufacturing of photovoltaic modules with wavy monolithic interconnects that tune front-contact layer sheet resistance, reducing or eliminating the need for front-contact grids, and allowing for non-rectangular shapes to maximize light exposure and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If transparent front-contact layer is used in thin-film photovoltaic devices, then the device structure is simplified and manufacturing is easier, but the layer exhibits high resistivity which reduces electrical efficiency

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidelectrical conductivity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the geometric parameters of the front-contact layer by introducing a wavy pattern instead of straight lines. This increases the effective conductive path length and reduces the sheet resistance impact, thereby improving electrical conductivity while maintaining the simplified transparent layer structure

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies curvature to the front-contact interconnect lines by designing them with wavy patterns rather than straight lines. This curvature increases the effective area and conductivity path of the front-contact layer, resolving the high resistivity issue while keeping the manufacturing process simple

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Reliability

If front-contact grid structures are added to reduce resistivity, then electrical conductivity is improved, but production costs increase and points of failure are introduced

Engineering Contradiction:

Improveelectrical conductivityVSAvoidgrid structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for separate front-contact grid structures by incorporating the conductivity function directly into the transparent front-contact layer through wavy patterning. This removes the additional grid layer and its associated manufacturing complexity and failure points

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of the transparent front-contact layer and the current-collecting grid into a single integrated wavy transparent contact pattern. This consolidation eliminates the need for separate grid structures while maintaining both transparency and conductivity functions

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If conventional rectangular photovoltaic modules are used, then manufacturing is straightforward, but the area coverage on non-rectangular surfaces is inefficient

Engineering Contradiction:

Improvearea coverage efficiencyVSAvoidmanufacturing complexity

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent introduces dynamic adaptability to the photovoltaic module design by making the interconnect pattern flexible and adjustable. The wavy pattern can be configured in different geometries to adapt to various surface shapes, enabling efficient coverage of non-rectangular surfaces while maintaining straightforward manufacturing processes

Inventive Principle:

Principle #15Dynamics

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 approach reduces production costs, increases module efficiency, enhances reliability, and provides a more uniform appearance while enabling flexible, efficient coverage of non-rectangular surfaces.

Implementation Method 1

wavy monolithic interconnects that tune front-contact layer sheet resistance

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

thin-film photovoltaic devices

Methodology Applied

Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP2834847B1Thin-film photovoltaic device with wavy monolithic interconnects

Publication Date: 2021.06.02 FLISOM AG

Figure 1A~1E
Figure 2A~2B
Figure 2C~2D

AI summary

A thin-film optoelectronic module device (100) and design method comprising at least three monolithically-interconnected cells (104, 106, 108) where at least one monolithically- interconnecting line (250) depicts a spatial periodic or quasi-periodic wave and wherein the optoelectronic surface of said thin-film optoelectronic module device (100) presents at least one set of at least three zones (210, 220, 230) having curves of substantially parallel monolithic interconnect lines. Border zones (210, 230) have a lower front-contact sheet resistivity than th at of internal zone (220). Said curves of substantially parallel interconnecting lines may comprise peaks of triangular or rounded shape, additional spatial periods that are smaller than a baseline period, and mappings from one curve to the adjacent curve such as in the case of non-rectangular module devices (100). The device (100) and design method are advantageous to reduce costs and materials to manufacture thin-film optoelectronic module devices (100) while increasing production yield, reliability, aesthetic appearance, and range of applications.