Radiation Detector With Nanoparticle Bandgap Engineering

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Solution Overview

Problem

Current radiation detectors face inefficiencies in detecting beta-rays due to high sensitivity to gamma-rays, leading to masked beta-ray detection and increased dark current, especially when using scintillator layers or thick organic semiconductor materials.

Innovation Solution

A radiation detector configuration with a first and second conductive layer and an intermediate layer containing organic semiconductor regions and particles with diameters between 1-20 nanometers, where the particles' bandgap energy is higher than the organic semiconductor region's, allowing direct energy transfer and suppressing light emission, enhancing sensitivity to beta-rays while reducing sensitivity to gamma-rays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If scintillator layers or thick organic semiconductor materials are used to increase detection efficiency, then sensitivity to gamma-rays increases, but sensitivity to beta-rays decreases due to masking and dark current increases

Engineering Contradiction:

Improvedetection efficiencyVSAvoidbeta-ray detection sensitivity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the particle size parameter to a specific range (1-20 nm) and adjusts the bandgap energy relationship between particles and organic semiconductor material. This parameter optimization allows the detector to maintain high gamma-ray detection efficiency while suppressing beta-ray masking and reducing dark current, resolving the contradiction between overall detection efficiency and beta-ray detection sensitivity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite intermediate layer combining inorganic particles with specific bandgap energy and organic semiconductor materials. This composite structure enables selective detection: the particles absorb gamma-rays efficiently while the organic semiconductor material with lower bandgap energy converts beta-ray energy to electrical signals without being masked by gamma-ray-induced light emission, thus resolving the sensitivity contradiction

Inventive Principle:

Principle #40Composite materials

2Reliability

If particles with diameter not less than 1 nanometer and not more than 20 nanometers are used in the intermediate layer, then direct energy transfer occurs and light emission is suppressed, but the manufacturing precision requirement increases

Engineering Contradiction:

Improveenergy transfer efficiencyVSAvoidparticle size control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent specifies a particle diameter range of 1-20 nm that balances energy transfer efficiency with manufacturability. This parameter range is narrow enough to ensure quantum confinement effects and efficient energy transfer, yet broad enough to allow practical synthesis methods, resolving the contradiction between performance and manufacturing precision

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If the intermediate layer is made thinner to reduce complexity, then beta-ray detection sensitivity improves, but the detection efficiency for gamma-rays decreases

Engineering Contradiction:

Improveintermediate layer thicknessVSAvoidgamma-ray detection efficiency

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent uses a composite material system where inorganic particles with high atomic numbers provide gamma-ray absorption in a thin layer, while the organic semiconductor material provides beta-ray to electrical signal conversion. This composite approach maintains gamma-ray detection efficiency in thinner layers, resolving the contradiction between layer thickness/complexity and detection efficiency

Inventive Principle:

Principle #40Composite materials

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 achieves high sensitivity and selectivity for beta-ray detection with reduced dark current and complexity, allowing for efficient beta-ray detection even in the presence of gamma-rays, and simplifies the detection circuit with a thinner intermediate layer.

Implementation Method 1

A first bandgap energy of the plurality of particles is larger than a second bandgap energy of the organic semiconductor region... allowing direct energy transfer

Methodology Applied

Scientific EffectEnergy transfer:

Implementation Method 2

a radiation detector includes a first conductive layer, a second conductive layer, and an intermediate layer... for efficient beta-ray detection

Methodology Applied

Scientific EffectRadiation detection:

Data Source

PatentUS10193093B2Radiation detector

Publication Date: 2019.01.29 KK TOSHIBA

AI summary

According to one embodiment, a radiation detector includes a first conductive layer, a second conductive layer, and an intermediate layer. The intermediate layer is provided between the first conductive layer and the second conductive layer. The intermediate layer includes an organic semiconductor region and a plurality of particles. The organic semiconductor region including a portion provided around the particles. A diameter is not less than 1 nanometer and not more than 20 nanometers for at least a portion of the particles. A first bandgap energy of the plurality of particles is larger than a second bandgap energy of the organic semiconductor region.