Ultraviolet Light Target With Aluminum Oxide Interlayer
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Solution Overview
Problem
Current ultraviolet light sources, such as mercury-xenon lamps and light-emitting diodes, face issues with low luminous efficiency, large size, safety concerns, and environmental impact, while electron beam-excited sources struggle with limited output efficiency due to challenges in processing sapphire substrates for improved light extraction.
Innovation Solution
A target for ultraviolet light generation is developed using a sapphire substrate with an interlayer containing oxygen and aluminum atoms, combined with a luminous layer of oxide crystals with an activator agent, which reduces reflection and enhances light extraction efficiency by forming fine structures through thermal treatment of an aluminum hydroxide film or powder-form aluminum oxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the surface of sapphire substrate is roughened to increase light extraction efficiency, then ultraviolet light extraction efficiency is improved, but manufacturing difficulty increases due to extreme hardness and chemical inertness
Solution Approach 1:
An aluminum oxide interlayer is introduced as an intermediary between the sapphire substrate and the luminous layer. This interlayer can be easily formed by thermal treatment of aluminum hydroxide and provides the necessary surface roughness for light extraction enhancement without requiring direct processing of the hard sapphire substrate. The interlayer acts as a mediator that achieves the desired optical performance while avoiding the manufacturing difficulties of processing sapphire directly.
Solution Approach 2:
The original single-layer sapphire substrate structure is segmented into a multi-layer structure consisting of the sapphire substrate and an additional aluminum oxide interlayer. This segmentation allows the surface roughening function to be assigned to the interlayer rather than the substrate itself, enabling independent optimization of each layer's properties and simplifying the manufacturing process.
2Illumination intensity
If conventional ultraviolet light sources are used, then sufficient light intensity is achieved, but luminous efficiency is low and device size is large
Solution Approach 1:
The invention changes the physical and chemical parameters of the interface between substrate and luminous layer by introducing an aluminum oxide interlayer with specific optical properties. This parameter change in the interface structure reduces reflection losses and enhances light extraction, thereby improving luminous efficiency while maintaining sufficient light intensity.
3Weight of stationary object
If light-emitting diodes are used, then device size is reduced, but light output intensity is insufficient and application range is limited
Solution Approach 1:
The invention converts the naturally occurring aluminum hydroxide layer (which might be considered an impurity or defect) into a beneficial aluminum oxide interlayer through thermal treatment. This interlayer provides optical benefits that enhance light extraction, thereby enabling small-sized LED devices to achieve sufficient light output intensity for practical applications.
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 significantly increases ultraviolet light extraction efficiency, achieving higher peak intensities and light output efficiencies compared to traditional methods, even with sapphire substrates that are difficult to process, and maintains a stable and uniform light output.
Implementation Method 1
forming fine structures through thermal treatment of an aluminum hydroxide film
Implementation Method 2
thermal treatment of an aluminum hydroxide film or powder-form aluminum oxide
Implementation Method 3
electron beam-excited ultraviolet light sources having a structure in which ultraviolet light is excited by irradiating targets with electron beams
Implementation Method 4
The luminous layer receives electron beams and generates ultraviolet light
Implementation Method 5
it is possible to reduce reflection on the surface of the supporting substrate and increase the light extraction efficiency
Data Source
AI summary
A target for ultraviolet light generation 20A includes a sapphire substrate 21 that transmits ultraviolet light UV, an interlayer 22 that is in contact with the sapphire substrate 21, includes oxygen atoms and aluminum atoms in a composition, and transmits ultraviolet light UV, and a luminous layer 23 that is provided on the interlayer 22, includes oxide crystals containing rare earth elements to which an activator agent is added, and receives electron beams EB so as to generate ultraviolet light UV.