AlN Polytypoid Fluorescent Substance for FED Luminance Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sulfide fluorescent substances, such as ZnS, decompose under the conditions of a low energy cathode-ray display screen, leading to luminance deterioration and color deviation in field emission type displays, especially for blue fluorescent substances, which are more vulnerable to temperature-induced degradation.
Innovation Solution
A fluorescent substance with an AlN polytypoid structure and a luminescence center element, such as Eu or Mn, is used, which maintains high luminous efficiency and stability even under high temperature and high current density conditions, preventing luminance degradation and color deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sulfide fluorescent substances (ZnS) are used in field emission type displays, then the fluorescent substances can be excited by electron beams to produce light, but the fluorescent substances decompose under low energy cathode-ray display conditions, leading to luminance deterioration and color deviation
Solution Approach 1:
The patent changes the chemical composition parameters of the fluorescent substance by using an AlN polytypoid structure with specific metal elements (M) and non-metal elements (X) substituting for Al and N respectively. This compositional parameter change fundamentally improves the chemical stability and resistance to decomposition under electron beam excitation, directly resolving the contradiction between reliability and compositional stability.
Solution Approach 2:
The patent employs a composite fluorescent substance structure where the AlN polytypoid matrix is combined with specific luminescence center elements. This composite material approach creates a more stable and durable fluorescent substance that resists decomposition while maintaining luminous efficiency, thereby resolving the contradiction between reliability and compositional stability.
2Illumination intensity
If high current density is applied to excite the fluorescent substances, then sufficient luminous efficiency can be achieved, but the temperature of the fluorescent substance rises to about 100°C, causing emission intensity degradation
Solution Approach 1:
The patent changes the thermal parameter characteristics by selecting specific metal elements (M) and non-metal elements (X) in the AlN polytypoid structure. These parameter changes result in improved thermal stability and resistance to temperature-induced emission degradation, allowing the fluorescent substance to maintain performance at elevated temperatures while achieving sufficient luminous efficiency through high current density excitation.
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 AlN polytypoid-based fluorescent substance exhibits enhanced temperature stability and luminance retention, ensuring consistent display performance and reducing the risk of color deviation in field emission type displays.
Implementation Method 1
a fluorescent substance to be employed in a light-emitting device... a layer comprising a fluorescent substance configured to be impinged by the electrons
Implementation Method 2
a light-emitting element configured to emit a light having a wavelength of 250 nm to 500 nm
Data Source
AI summary
A fluorescent substance is provided, with includes a matrix composed of a compound having an AlN polytypoid structure represented by the following general formula (1), and a luminescence center element:(Al,M)a(N,X)b (1)wherein, M is at least one metal excluding Al, X is at least one non-metal excluding N, and a and b are positive values.