Scintillator Layer Structure for High Luminescence and Low Afterglow
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Solution Overview
Problem
Existing scintillators suffer from low luminescence intensity due to low carrier recombination probability and afterglow caused by residual carriers, which are not adequately addressed in existing materials and structures.
Innovation Solution
A scintillator configuration with a substrate, buffer layer, luminescent unit, and conductive layers, including elements like Ga, Zn, In, Al, Cd, Mg, Ca, and Sr, and a second conductive layer to enhance carrier recombination and reduce afterglow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a scintillator uses a luminescent layer with high-speed response characteristics to reduce afterglow, then the fluorescence lifetime is shortened, but the luminescence intensity becomes low due to low probability of carrier recombination
Solution Approach 1:
The invention changes the electron concentration parameter of the luminescent layer to a specific range (1×10^16 to 1×10^18 cm^-3) to simultaneously achieve short fluorescence lifetime and high luminescence intensity. This parameter optimization resolves the contradiction by finding the optimal electron concentration that balances carrier recombination probability with response speed.
Solution Approach 2:
The invention uses ZnO as the base material doped with specific impurities (Ga, In, Al, Ca, or Sr) to create a composite luminescent layer. This composite structure enables both high-speed response and high luminescence intensity by combining the properties of the base material with the dopant elements, resolving the contradiction between response time and light output.
2Illumination intensity
If the electron concentration of the luminescent layer is increased to improve luminescence intensity, then carrier recombination probability increases, but afterglow intensity increases due to residual carriers
Solution Approach 1:
The invention optimizes the electron concentration to a specific range (1×10^16 to 1×10^18 cm^-3) that simultaneously achieves high luminescence intensity while minimizing afterglow. This precise parameter control ensures sufficient carrier recombination for bright luminescence while preventing excessive residual carriers that would cause afterglow.
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
The solution achieves reduced afterglow intensity and increased luminescence intensity by improving the luminescent unit structure, allowing for more efficient detection of charged particles.
Implementation Method 1
a luminescent unit which contains one or more elements that are selected from the group consisting of Ga, Zn, In, Al, Cd, Mg, Ca and Sr
Implementation Method 2
The scintillator emits light due to recombination of carriers excited in the scintillator
Implementation Method 3
converted into an electric signal by a photodetector such as a photoelectric tube
Data Source
AI summary
The present invention provides: a scintillator which is reduced in the intensity of the afterglow, while having increased luminous intensity; and a charged particle radiation apparatus. A scintillator according to the present invention is characterized in that: a base material, a buffer layer, a light emitting part and a first conductive layer are sequentially stacked in this order; the light emitting part contains one or more elements that are selected from the group consisting of Ga, Zn, In, Al, Cd, Mg, Ca and Sr; and a second conductive layer is provided between the base material and the light emitting part.