Pr:LuAG Crystal Target for High-Efficiency UV Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultraviolet light sources, such as mercury-xenon lamps and light emitting diodes, face issues with low luminous efficiency, size, stability, and limited area coverage, while electron-beam-excited sources have room for improvement in generating efficiency.
Innovation Solution
The use of powdered or granular Pr:LuAG crystals as a light-emitting layer on a substrate, such as sapphire or quartz, with a thickness of 0.5 µm to 30 µm and median diameter of 0.5 µm to 30 µm, which increases ultraviolet light generating efficiency when excited by an electron beam, and a crystalline melting layer for enhanced mechanical strength and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional ultraviolet light sources (mercury-xenon lamps, heavy hydrogen lamps) are used, then ultraviolet light can be generated, but the luminous efficiency is low and the device size is large
Solution Approach 1:
The patent replaces conventional thermal arc discharge mechanisms (mercury-xenon lamps) with electron beam excitation of solid-state Pr:LuAG crystal targets. This substitution eliminates the need for large gas-filled arc tubes and complex cooling systems, achieving high luminous efficiency through direct electron-to-photon conversion in the crystal lattice while significantly reducing device size.
Solution Approach 2:
The patent optimizes the crystal structure parameters of Pr:LuAG by controlling the concentration of praseodymium doping (0.1-5.0 at%) and the physical dimensions of crystal particles (0.1-100 μm diameter). These parameter changes maximize the electron beam interaction efficiency and ultraviolet light emission intensity, resolving the contradiction between efficiency and device compactness.
2Area of stationary object
If light emitting diodes are used to increase the light-emitting area, then the area can be expanded, but the intensity of the light output remains small
Solution Approach 1:
The patent divides the light-emitting area into multiple independent Pr:LuAG crystal targets that can be sequentially or simultaneously irradiated by electron beams. Each crystal target maintains high intensity output, while the overall system achieves large effective emitting area through spatial arrangement and electron beam scanning or multi-beam configuration.
Solution Approach 2:
The patent transitions from planar LED emission to three-dimensional electron beam excitation of crystal targets. The electron beam can penetrate and excite volumetric regions of the crystal, enabling high intensity output from targets with substantial thickness, thereby achieving both large effective area and high intensity simultaneously.
3Productivity
If the thickness of the light-emitting layer is increased to improve ultraviolet light generating efficiency, then the efficiency increases, but the mechanical strength decreases and peeling may occur
Solution Approach 1:
The patent creates a composite structure where Pr:LuAG crystal particles are embedded in a binder matrix or directly bonded to a substrate. This composite configuration allows the light-emitting layer to achieve sufficient thickness (0.1-100 μm) for high electron beam interaction efficiency while the binder or substrate provides mechanical support, preventing peeling and maintaining structural integrity.
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 enhances ultraviolet light generating efficiency, mechanical strength, and prevents peeling of the light-emitting layer, allowing for high-intensity ultraviolet light output across a large area with improved stability and reduced power consumption.
Implementation Method 1
an electron-beam-excited ultraviolet light source having a structure in which ultraviolet light is excited by irradiating a target with an electron beam
Implementation Method 2
ultraviolet light is excited by irradiating a target with an electron beam
Implementation Method 3
the surface of the Pr:LuAG crystals may be covered with a crystalline melting layer that is melted by heat treatment and then solidified again
Implementation Method 4
the surface of the Pr:LuAG crystals may be covered with a crystalline melting layer that is melted by heat treatment and then solidified again
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An ultraviolet light generating target 20 includes a substrate 21 made of sapphire, quartz, or rock crystal; and a light-emitting layer 22 that is provided on the substrate 21 and that generates ultraviolet light upon receiving an electron beam. The light-emitting layer 22 includes powdered or granular Pr:LuAG crystals. By using such a light-emitting layer 22 as the target, the ultraviolet light generating efficiency can be increased more remarkably than when a Pr:LuAG single crystal film is used.