Series-Connected Organic Solar Cell Coupling Structure

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Solution Overview

Problem

Photoelectric conversion modules with series-connected organic thin film solar cells experience inefficiencies due to reverse current generation, leading to differences in conversion efficiency between low-illuminance and high-illuminance environments.

Innovation Solution

Incorporating a coupling portion with a specific contact region configuration, where the length of the contact region in the coupling direction is 0.3 or greater, to minimize reverse current generation by optimizing the electrical coupling between photoelectric conversion elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If photoelectric conversion elements are coupled in series to increase output, then power generation capability is improved, but reverse current is generated at coupling portions causing efficiency difference between low-illuminance and high-illuminance environments

Engineering Contradiction:
Improvepower generation capabilityVSAvoidphotoelectric conversion efficiency stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies local quality by creating a specific contact region structure at the coupling portion where the second electrode of one photoelectric conversion element contacts the first electrode of the adjacent element. The contact region is designed with specific dimensional ratios (X/(Y-X) ≥ 0.3) to locally optimize electrical coupling and minimize reverse current generation, while the rest of the photoelectric conversion elements maintain their standard structure for high power generation capability.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If a through hole coupling structure is used to connect electrodes, then electrical coupling is achieved, but reverse current is generated in the electrode near the coupling portion

Engineering Contradiction:
Improveelectrical couplingVSAvoidreverse current
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by modifying the geometric parameters of the contact region in the through-hole coupling structure. Specifically, it defines the ratio X/(Y-X) ≥ 0.3, where X is the contact region length and Y is the total length between partition portions. By optimizing this dimensional parameter, the patent reduces reverse current generation while maintaining effective electrical coupling between series-connected photoelectric conversion elements.

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 configuration reduces the difference in photoelectric conversion efficiency across varying illuminance conditions, enhancing overall efficiency and stability of the module.

Implementation Method 1

photoelectric conversion layer, and a second electrode that are stacked in this order on or above a base serving as a support substrate

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4006979B1Photoelectric conversion module, electronic device, and power supply module
Publication Date: 2024.01.03 RICOH CO LTD
  • EP4006979B1 patent drawingFigure 1~3
  • EP4006979B1 patent drawingFigure 4A~4F
  • EP4006979B1 patent drawingFigure 4G~4J

AI summary

A photoelectric conversion module (10) includes photoelectric conversion elements (31,32) electrically coupled. The photoelectric conversion elements (31,32) each sequentially include first electrode (12), photoelectric conversion layer (15), and second electrode (18). The photoelectric conversion module (10) includes first photoelectric conversion element (31), second photoelectric conversion element (32), coupling portion (16) to couple the first and second photoelectric conversion elements (31,32) in series, first partition portion (12"), and second partition portion (12"). The first electrode (12) or the second electrode (18) forming the first photoelectric conversion element (31) includes a contact region in contact with the coupling portion (16). A value of X/(Y―X) is 0.3 or greater, where X denotes a length of the contact region and Y denotes a predetermined length in the coupling direction around the contact region.