Solar Cell Module Edge Sealing Against Water Vapor Discoloration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Solar cell modules installed in devices like watches face discoloration issues at the outer peripheral end of the photoelectric conversion layer due to exposure to water vapor and oxygen, which affects both functionality and appearance.

Innovation Solution

A solar cell module design where the perimeter of the photoelectric conversion layer is positioned inside the base material perimeter, with a colored layer covering areas not overlapping with the conversion layer, and a sealing layer to inhibit water and oxygen ingress, along with a configuration that reduces color contrast.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the photoelectric conversion layer is formed as far as the outer peripheral end of the base material, then the light-receiving area is maximized, but the outer peripheral end face of the photoelectric conversion layer is exposed to water vapor and oxygen causing discoloration

Engineering Contradiction:
Improvelight-receiving areaVSAvoidexposure to water vapor and oxygen
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

A sealing layer is introduced as an intermediary between the photoelectric conversion layer and the external environment. This sealing layer covers the outer peripheral end face of the photoelectric conversion layer, preventing direct exposure to water vapor and oxygen while allowing the photoelectric conversion layer to extend to the outer peripheral end of the base material for maximum light reception.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the photoelectric conversion layer is removed from the outer periphery to prevent discoloration, then exposure to water vapor and oxygen is prevented, but color contrast on the light-receiving surface increases impairing appearance

Engineering Contradiction:
Improveprotection from water vapor and oxygenVSAvoidappearance uniformity
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The sealing layer serves as a protective intermediary that allows the photoelectric conversion layer to extend to the edge without direct environmental exposure. This eliminates the need to remove the photoelectric conversion layer from the periphery, thereby maintaining appearance uniformity while still preventing discoloration through the sealing barrier.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a sealing layer is added to cover the solar battery cell, then discoloration is inhibited, but device complexity increases

Engineering Contradiction:
Improveresistance to discolorationVSAvoidnumber of layers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing layer performs multiple functions simultaneously: it seals the outer peripheral end face of the photoelectric conversion layer to prevent water vapor and oxygen ingress, provides mechanical protection, and can contribute to the overall structural integrity of the solar cell module. This multi-functionality justifies the addition of the layer despite the increase in device complexity.

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

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 design effectively inhibits discoloration of the photoelectric conversion layer and maintains an aesthetically pleasing appearance over time.

Implementation Method 1

a solar battery cell formed over the base material and in which a photoelectric conversion layer is provided

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 2

a sealing layer that covers the solar battery cell... inhibiting discoloration of the photoelectric conversion layer

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP4642196A1Solar cell module
Publication Date: 2025.10.29 PANASONIC HOLDINGS CORP
  • EP4642196A1 patent drawingFigure 1
  • EP4642196A1 patent drawingFigure 2
  • EP4642196A1 patent drawingFigure 3

AI summary

A solar cell module 1 according to an example of an embodiment includes a base material 2, a solar battery cell 3 disposed over the base material 2, and a sealing layer 30 that covers the solar battery cell 3. The solar battery cell 3 includes a photoelectric conversion layer 10, a first electrode layer 11 disposed on a first surface side of the photoelectric conversion layer 10, and a second electrode layer 12 disposed on a second surface side of the photoelectric conversion layer 10. A perimeter of the photoelectric conversion layer 10 is positioned inside a perimeter of the base material 2 in plan view. A colored layer 40 is disposed at least in an area not overlapping with the photoelectric conversion layer 10.