Multi-Junction Solar Cell Layout for Stable Series Connection

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Solution Overview

Problem

Existing solar cells face challenges in achieving high efficiency due to issues with stable series connection and leakage currents when dividing conductive films, particularly in multi-junction cells.

Innovation Solution

The design incorporates a first photoelectric conversion region with a thinner second thickness than the first, ensuring non-overlap with the conductive region, and includes specific material configurations to stabilize the division and reduce leakage currents, such as using copper oxide and compound layers with controlled thickness ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the conductive film is divided into multiple conductive regions to enable series connection, then the power output is improved, but leakage currents occur and connection stability deteriorates

Engineering Contradiction:
Improvepower outputVSAvoidconnection stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The conductive film is divided into multiple conductive regions (first conductive region and second conductive region) that are electrically isolated from each other. This segmentation enables series connection between multiple photoelectric conversion regions, increasing the overall power output while maintaining connection stability through proper isolation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An insulating film is introduced as an intermediary layer between the first and second conductive regions. This insulating film prevents leakage currents while allowing the series connection to function properly, thus improving both power output and connection stability simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If the conductive film is divided into multiple conductive regions, then the power output is improved, but leakage currents increase

Engineering Contradiction:
Improvepower outputVSAvoidleakage currents
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The insulating film serves as a mediator that blocks leakage currents between the first and second conductive regions. By placing this insulating layer at the interface between conductive regions, energy loss through leakage is minimized while the series connection for power enhancement is maintained.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating film is selectively placed only in specific regions where leakage currents would occur between conductive regions, rather than throughout the entire structure. This localized approach prevents energy loss without compromising the overall electrical connectivity needed for power generation.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If the photoelectric conversion layer thickness is reduced in certain regions, then the manufacturing precision is improved, but the photoelectric conversion efficiency may deteriorate

Engineering Contradiction:
Improvethickness control precisionVSAvoidphotoelectric conversion efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The photoelectric conversion layer has different thicknesses in different regions: a first thickness in the first photoelectric conversion region and a second thickness (greater than the first) in the second photoelectric conversion region. This local quality variation allows precise thickness control in critical areas while maintaining adequate photoelectric conversion efficiency in other regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent varies the thickness of the photoelectric conversion layer in the vertical dimension to optimize both manufacturing precision and photoelectric conversion efficiency. By controlling thickness in the Z-direction rather than changing lateral dimensions, the patent achieves precise manufacturing control without sacrificing conversion efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 enhances efficiency by stabilizing series connections and reducing leakage currents, resulting in a solar cell with improved performance, up to 1.4 times more efficient than reference examples.

Implementation Method 1

a first photoelectric conversion layer including a first photoelectric conversion region and a second photoelectric conversion region

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP4583168A1Solar cell, multi-junction solar cell, solar cell module, and solar cell power generation system
Publication Date: 2025.07.09 KK TOSHIBA
  • EP4583168A1 patent drawingFigure 1~2
  • EP4583168A1 patent drawingFigure 3
  • EP4583168A1 patent drawingFigure 4A~4H

AI summary

According to one embodiment of the invention, a solar cell includes a first conductive layer, a first counter conductive layer, and a first photoelectric conversion layer. The first counter conductive layer includes a first conductive region. A direction from the first conductive layer to the first conductive region is along a first direction. The first photoelectric conversion layer includes a first photoelectric conversion region and a second photoelectric conversion region. The first photoelectric conversion region is provided between the first conductive layer and the first conductive region in the first direction. The second photoelectric conversion region does not overlap the first conductive region in the first direction. A second thickness of the second photoelectric conversion region along the first direction is thinner than a first thickness of the first photoelectric conversion region along the first direction.