UV Light Source and Photoluminescent Layer for White LED
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Solution Overview
Problem
Traditional White Organic Light Emitting Diodes (WOLEDs) face challenges in manufacturing complexity, low lighting efficiency, and poor quality of white light due to interference between colored light-emitting materials and the need for precise doping concentrations.
Innovation Solution
A light emitting device comprising a substrate with an ultraviolet light source generating panel and a photoluminescent layer that uses photoluminescent blue, green, and red materials to generate white light when irradiated by ultraviolet light, with a simplified structure that includes an anode, cathode, and electroluminescent material layers, and a power supply to create a voltage difference, allowing for easier manufacturing and improved light stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a WOLED with multiple light-emitting layers is used to generate white light, then the quality of white light is improved, but the manufacturing complexity increases and lighting efficiency decreases
Solution Approach 1:
The device is divided into two independent modules: an ultraviolet light source generating panel and a photoluminescent layer. The photoluminescent layer is further segmented into multiple independent light-emitting layers (red, green, blue) that can be manufactured separately and then assembled with the UV panel, simplifying the overall manufacturing process while maintaining high quality white light output.
Solution Approach 2:
An ultraviolet light source is introduced as an intermediary to excite the photoluminescent materials. The UV light acts as a mediator that converts non-emissive photoluminescent materials into emissive states, enabling the generation of high-quality white light without requiring complex direct emission structures.
2Illumination intensity
If a WOLED with multiple light-emitting layers is used to generate white light, then the quality of white light is improved, but the lighting efficiency is reduced due to energy absorption between layers
Solution Approach 1:
By segmenting the light generation process into separate UV emission and photoluminescent conversion stages, energy loss through inter-layer absorption is eliminated. Each photoluminescent layer is independently excited by UV light, preventing energy waste from adjacent emissive layers.
Solution Approach 2:
The ultraviolet light source serves as an intermediary that provides high-energy excitation without being absorbed by the photoluminescent materials. This intermediary approach enables efficient energy transfer from UV to visible light wavelengths without the energy loss that occurs when multiple emissive layers are stacked together.
3Ease of manufacture
If a WOLED with a single light-emitting layer is used, then the manufacturing process is simpler, but the quality of white light is poor due to interference between colored light-emitting materials
Solution Approach 1:
The device is segmented into a UV light source panel and separate photoluminescent layers. This segmentation allows each layer to be optimized independently for its specific wavelength emission, avoiding the interference problems that occur when multiple colored materials are mixed in a single layer, while keeping the manufacturing process relatively simple.
4Ease of manufacture
If traditional WOLED structures are used, then the device can be manufactured, but the luminous stability is low and the service life is short
Solution Approach 1:
Segmenting the device into a UV light source panel and photoluminescent layers isolates the emissive materials from direct electrical contact and potential degradation sources. The UV panel handles electrical stress while the photoluminescent layers handle light emission, improving overall device stability and lifespan.
Solution Approach 2:
The UV light source acts as an intermediary that indirectly excites the photoluminescent materials without requiring them to be in direct contact with electrical contacts. This indirect excitation method reduces electrical stress and chemical degradation on the photoluminescent materials, enhancing their stability and extending device life.
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 simplifies the manufacturing process, enhances luminous stability, and extends the life of the light emitting device while producing high-quality white light by mixing blue, green, and red light emissions effectively.
Implementation Method 1
an electroluminescent ultraviolet light emitting material layer disposed between the anode layer and the cathode layer, the electroluminescent ultraviolet light emitting material layer being used for generating the ultraviolet light when there is a predetermined voltage difference between the anode layer and the cathode layer
Implementation Method 2
a photoluminescent blue light emitting material used for emitting blue light when the photoluminescent blue light emitting layer is irradiated by the ultraviolet light
Implementation Method 3
a photoluminescent green light emitting material used for emitting green light when the photoluminescent green light emitting layer is irradiated by the ultraviolet light
Implementation Method 4
a photoluminescent red light emitting material used for emitting red light when the photoluminescent red light emitting layer is irradiated by the ultraviolet light
Data Source
AI summary
A white light emitting diode device includes a substrate, an ultraviolet light source generating panel and a photoluminescent layer. The ultraviolet light source generating panel is disposed on a first surface of the substrate. The ultraviolet light source generating panel is used for generating ultraviolet light. The photoluminescent layer is disposed on a second surface of the substrate. The photoluminescent layer is used for generating white light when the photoluminescent layer is irradiated by the ultraviolet light.