Segmented Infrared Detector Regions for Sensitivity

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Solution Overview

Problem

The detection sensitivity of infrared light detectors is limited due to saturation of electric charge in the first electronic region, leading to a decrease in sensitivity when the source-drain voltage exceeds a certain threshold, limiting the applicability of existing infrared light detectors.

Innovation Solution

The infrared light detector is designed with a plurality of electrically independent first electronic regions arranged in a specific direction, allowing each region to be switched between disconnected and connected statuses, ensuring a sufficient high-low energy difference for electron transition, thereby enhancing detection accuracy and sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single first electronic region is used to detect infrared light, then the device structure is simple, but the detection sensitivity saturates quickly due to limited charge accumulation capacity

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The single first electronic region is divided into multiple first electronic regions (first through fourth regions) arranged in sequence. Each region can independently accumulate charge carriers, effectively increasing the total charge accumulation capacity while maintaining a relatively simple overall device structure. This segmentation allows continuous detection without early saturation.

Inventive Principle:
Principle #1Segmentation

2Power

If the source-drain voltage is increased to enhance signal current, then the signal strength improves, but the detection sensitivity decreases due to charge saturation in the first electronic region

Engineering Contradiction:
Improvesignal currentVSAvoiddetection sensitivity
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

By dividing the first electronic region into multiple segments, the charge accumulation capacity is increased, allowing the detector to maintain high detection sensitivity even at higher source-drain voltages that generate stronger signal currents. The segmented structure prevents charge saturation that would otherwise occur in a single region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple first electronic regions are arranged in a spatial sequence (along the transport direction), extending the charge accumulation in one dimension. This spatial arrangement allows the system to handle higher voltage conditions while maintaining sensitivity by distributing charge accumulation across multiple locations.

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

3Power

If electrons are allowed to escape to the conduction channel to generate signal, then the detection signal is produced, but the charge accumulation in the first electronic region becomes limited

Engineering Contradiction:
Improvesignal generationVSAvoidcharge accumulation capacity
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The segmentation of the first electronic region into multiple regions creates multiple charge accumulation zones. Electrons can escape from any of these regions to the conduction channel, providing multiple pathways for signal generation while the remaining regions continue to accumulate charge, thereby maintaining overall charge accumulation capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multiple first electronic regions enable continuous charge accumulation and electron escape processes. While electrons escape from one region to generate signal, other regions continue to accumulate charge, ensuring the detection process can continue without interruption or saturation.

Inventive Principle:
Principle #20Continuity of useful action

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 significantly improves the detection accuracy and sensitivity of infrared light by allowing electrons to easily escape to the conduction channel, enabling a higher source-drain voltage and increased signal current, thus overcoming the limitations of single region detectors.

Implementation Method 1

an oscillating electric field is formed in a direction perpendicular to a first electronic region (2 direction) by a light coupling mechanism. By this oscillating electric field, electrons are transitioned from the ground sub-band (electron energy level ε 0 ) to the excited sub-band of the quantum well

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

The electrons transitioned to the excited sub-band escape from a potential barrier of the quantum well in the tunneling process

Methodology Applied
Scientific EffectQuantum Tunneling:

Data Source

PatentEP2426738B1Infrared light detector
Publication Date: 2019.10.02 THE JAPAN SCI & TECH AGENCY
  • EP2426738B1 patent drawingFigure 1
  • EP2426738B1 patent drawingFigure 2(a)~2(b)
  • EP2426738B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is an infrared light detector 100 with a plurality of first electronic regions 10 which are electrically independent from each other and arranged in a specific direction, formed by dividing a single first electronic region. An outer electron system which is electrically connected to each of the plurality of first electronic regions 10 in a connected status is configured such that an electron energy level of excited sub-bands of each of the plurality of first electron regions 10 in a disconnected status is sufficiently higher than a Fermi level of each of second electronic regions 20 opposed to each of the first electronic regions 10 in a conduction channel 120.