Red Phosphor Material for High-Energy Light Sources
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Solution Overview
Problem
Conventional red phosphors used in high-emission energy applications have insufficient luminous efficiency and poor temperature characteristics, leading to issues with ambient temperature rise, especially in high-emission energy regions.
Innovation Solution
A phosphor material with the formula A2-v-w-x-yBvLnwEuxSmyM2-zDzO8 is developed, where A is an alkaline-earth metal, B is an alkali metal, Ln is a rare-earth element other than Eu and Sm, and M is W or Mo, with specific ratios of v, w, x, y, and z, which enhances luminous efficiency and temperature stability by charge compensation and increased melting point, allowing for high-energy performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional red phosphors are used in high-emission energy applications, then emission energy can be achieved, but luminous efficiency is insufficient and temperature characteristics are poor
Solution Approach 1:
The patent modifies the chemical composition parameters of the phosphor material by incorporating specific ratios of Eu3+ (0.05-0.5), Sm3+ (0-0.1), and Ln3+ (0.1-0.6) ions, along with adjusting the M2+/M4+ ratio (1.5-3.0). These parameter changes optimize both luminous efficiency and temperature characteristics simultaneously, resolving the contradiction between energy loss and reliability.
Solution Approach 2:
The patent creates a composite phosphor material combining multiple rare-earth elements (Eu, Sm, Ln) with tungsten or molybdenum oxide in a specific crystalline structure. This composite approach leverages the complementary properties of each element: Eu3+ for red emission, Sm3+ for temperature stabilization, and Ln3+ for enhanced efficiency, achieving both high luminous efficiency and excellent temperature characteristics.
2Power
If high emission energy is required for projector and vehicle headlamp applications, then ambient temperature rises, but conventional phosphors cannot maintain performance at high temperatures
Solution Approach 1:
The patent converts the harmful effect of high temperature into a beneficial feature by selecting rare-earth elements with appropriate thermal properties. Sm3+ and Ln3+ ions are specifically chosen for their ability to stabilize the phosphor structure at elevated temperatures, transforming the thermal challenge into an opportunity to demonstrate superior temperature characteristics that enable high-power applications.
3Ease of manufacture
If conventional phosphor compositions are used, then manufacturing is simple, but luminous efficiency and temperature stability are insufficient
Solution Approach 1:
The patent maintains manufacturing simplicity by using a single-phase crystalline structure that can be produced through conventional ceramic processing methods. The complexity is managed through precise control of chemical composition parameters rather than complex processing steps, achieving high luminous efficiency while keeping manufacturing straightforward.
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 phosphor material exhibits high luminous efficiency and excellent temperature characteristics, maintaining luminance stability even at high temperatures, making it suitable for high-energy applications like projector and vehicle headlamp light sources.
Implementation Method 1
A phosphor material given by a compositional formula Ca2-2xLixEuxW2O8 or the like is known as a red phosphor which can be excited in a wavelength range from near-ultraviolet to blue and which has an Eu3+ luminescent center to emit light in the red region
Data Source
AI summary
A phosphor material according to an embodiment of the present disclosure contains a major component represented by the formula A2-v-w-x-yBvLnwEuxSmyM2-zDzO8, where A is one or more elements selected from the group consisting of alkaline-earth metal elements; B is one or more elements selected from the group consisting of alkali metal elements; Ln is one or more elements selected from the group consisting of rare-earth elements other than Eu and Sm; M is one or more elements selected from the group consisting of W and Mo; D is one or more elements selected from the group consisting of Nb and Ta; and v, w, x, y, and z satisfy the inequalities 0≦v≦0.5, 0.15≦x+y≦0.7, 0≦y≦0.05, and 0<z≦1.7 and the equation w+x+y=v+z.