Electromagnetic Wave Detecting Element Common Electrode Line Position

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Solution Overview

Problem

Existing electromagnetic wave detecting elements with common electrode lines disposed at the illumination surface side of semiconductor layers suffer from reduced light utilization efficiency due to the high resistivity of transparent conductive materials, which increases wiring load and capacity, preventing effective response.

Innovation Solution

The common electrode line is formed further downstream of the electromagnetic wave irradiation surface, using a light-shielding, low-resistance wiring material to supply bias voltage via contact holes, thus eliminating wave shielding and maintaining efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If common electrode lines are disposed at the illumination surface side of the semiconductor layer to supply bias voltage, then the wiring resistance is reduced and charge supply is improved, but the light utilization efficiency decreases due to shielding of electromagnetic waves

Engineering Contradiction:
Improvecharge supply reliabilityVSAvoidlight utilization efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent resolves the contradiction by moving the common electrode line from the illumination surface side (two-dimensional plane blocking light) to the non-illumination surface side (different spatial dimension), allowing light to pass through the semiconductor layer without obstruction while still providing bias voltage through vertically positioned contact holes

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

Solution Approach 2:

The patent introduces contact holes as intermediary structures that penetrate the semiconductor layer to connect the common electrode line on the non-illumination surface side with the upper electrodes, enabling electrical connection without placing conductive material in the light path

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If transparent conductive materials are used for upper electrodes to maintain light transmission, then light utilization efficiency is improved, but the wiring load (resistance and capacity) increases and desired response cannot be realized

Engineering Contradiction:
Improvelight utilization efficiencyVSAvoidresponse speed
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies different material qualities to different regions: transparent conductive materials are used only for the upper electrodes where light transmission is critical, while the common electrode line uses low-resistance opaque conductive material where only electrical performance matters, as the common electrode is positioned where it does not interfere with light

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent separates the electrical function (common electrode line) from the optical function (upper electrodes) by positioning the common electrode line in a different spatial dimension (non-illumination surface side), allowing optimization of each component's material properties for its specific function

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 prevents a decrease in electromagnetic wave utilization efficiency at sensor portions, even with a common electrode line, by ensuring that the common electrode line does not obstruct the electromagnetic waves, thereby maintaining effective detection.

Implementation Method 1

a semiconductor layer 6 at which charges are generated due to light being illuminated

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

an upper electrode 7 that is formed by a light-transmissive, electrically-conductive member at an illumination surface side of the semiconductor layer 6 at which light is illuminated, and that applies bias voltage to the semiconductor layer 6

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

a lower electrode 14 that is formed at the light non-illumination surface side of the semiconductor layer 6, and collects charges that are generated at the semiconductor layer 6

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2731136B1Electromagnetic wave detecting element
Publication Date: 2020.01.15 FUJIFILM CORP
  • EP2731136B1 patent drawingFigure 1
  • EP2731136B1 patent drawingFigure 2
  • EP2731136B1 patent drawingFigure 3A~3B

AI summary

The present invention is to provide an electromagnetic wave detecting element that can prevent a decrease in light utilization efficiency at sensor portions. The sensor portions are provided so as to correspond to respective intersection portions of scan lines and signal lines, and have semiconductor layer that generate charges due to electromagnetic waves being irradiated, and at whose electromagnetic wave irradiation surface sides upper electrodes are formed, and at whose electromagnetic wave non-irradiation surface sides lower electrodes are formed. Bias voltage is supplied to the respective upper electrodes via respective contact holes by a common electrode line that is formed further toward an electromagnetic wave downstream side than the semiconductor layer.