Epitaxial Solar Cell Isolation for Soldering Reliability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional flexible solar cells face issues such as current leakage and short circuits due to the direct exposure of the epitaxial active layer's side wall during the solder interconnecting process, which affects their performance.

Innovation Solution

The solar cell device incorporates an isolation section within the epitaxial active structure that divides it into first and second active sections, preventing direct contact between the interconnecting strip and the side wall, and uses a reflection reducing layer to minimize adhesion of conductive adhesive.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the epitaxial active layer side wall is directly exposed, then the manufacturing process is simpler, but current leakage and short circuits occur during solder interconnecting

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidelectrical reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

An isolation layer is introduced as an intermediary component between the epitaxial active layer and the external environment. This isolation layer covers the side wall of the epitaxial active layer, preventing direct contact between conductive adhesive and the active layer, thereby eliminating current leakage and short circuit issues while maintaining manufacturing feasibility

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The side wall of the epitaxial active layer is segmented by introducing an isolation layer that divides the continuous side wall surface into isolated regions. This segmentation prevents the formation of continuous conductive paths that would cause current leakage, while the isolation layer itself remains electrically insulating

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If conductive adhesive is applied for interconnecting, then flexible solar cell manufacturing is enabled, but adhesion to the epitaxial active layer side wall causes electrical faults

Engineering Contradiction:

Improveflexible solar cell manufacturing capabilityVSAvoidelectrical performance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The isolation layer serves as a mediator that allows the conductive adhesive to be applied for interconnecting flexible solar cells while preventing the adhesive from adhering to the epitaxial active layer side wall. The isolation layer is positioned between the adhesive and the active layer, enabling the manufacturing process to proceed without electrical faults

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If no isolation structure is used, then device complexity is reduced, but direct contact between interconnecting strip and side wall causes short circuits

Engineering Contradiction:

Improvestructural complexityVSAvoidelectrical insulation

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

An isolation layer is introduced as a simple intermediary structure that prevents direct contact between the interconnecting strip and the epitaxial active layer side wall. This single-layer addition provides effective electrical insulation without requiring complex multi-component isolation structures

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The isolation layer is implemented as a thin film structure that covers the side wall of the epitaxial active layer. This thin film provides adequate electrical insulation while minimizing the increase in device complexity and maintaining a compact structure

Inventive Principle:

Principle #30Flexible shells and thin films

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 configuration reduces the likelihood of current leakage and short circuits, enhancing the reliability of the solar cell devices by ensuring proper spacing and minimizing contact during soldering processes.

Implementation Method 1

epitaxially growing an epitaxial active structure on the stopping layer, the epitaxial active structure including a contact layer contacting with the stopping layer

Methodology Applied

Scientific EffectEpitaxial growth: Epitaxy

Implementation Method 2

depositing a metal material on the patterned photoresist layer and the portion of the contact layer

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentUS12464848B2Solar cell device and method for producing the same

Publication Date: 2025.11.04 TIANJIN SANAN OPTOELECTRONICS

AI summary

A solar cell device includes a supporting substrate, and an epitaxial active structure that is disposed on the supporting substrate. The epitaxial active structure has a bottom surface adjacent to the supporting substrate and a top surface opposite to the bottom surface, and is formed with an isolation section that extends from the top surface to the bottom surface. A method for producing the solar cell device is also disclosed.