OLED Optical Resonator Photolithographic Structuring
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Solution Overview
Problem
Existing methods for producing organic light-emitting diodes (OLEDs) face challenges in achieving precise alignment of shadow masks and multiple deposition steps, leading to complex and inefficient processes for generating full-color displays or light sources, with issues such as dust generation and insufficient color saturation and power efficiency.
Innovation Solution
A photolithographic process using a lossy optical resonator with a photochemically crosslinkable emitter layer and hole conductor layer of varying thicknesses, structured with a grayscale mask to achieve different optical path lengths and colors in a single step, allowing for the generation of a wide range of colors without the need for multiple alignments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If shadow masks are used for multiple deposition steps to produce full-color OLEDs, then color variety is achieved, but process complexity and alignment difficulty increase significantly
Solution Approach 1:
The patent combines multiple deposition steps into a single step by using a single layer containing multiple dyes with different emission colors. Instead of depositing separate layers for red, green, and blue colors using multiple shadow masks, the invention incorporates all color-emitting dyes into one emitter layer that can be deposited in a single vacuum deposition process, thereby eliminating the need for multiple alignment operations.
Solution Approach 2:
The patent segments the emission spectrum by incorporating different dyes at specific positions within the emitter layer. By strategically placing dyes with different emission wavelengths at different locations or depths within the same layer, the invention achieves full-color emission without requiring multiple physical layers or masks, thus simplifying the overall device structure while maintaining color versatility.
2Adaptability or versatility
If multiple shadow mask alignment steps are performed, then full-color display capability is achieved, but manufacturing precision requirements become extremely stringent
Solution Approach 1:
The invention merges the function of multiple shadow masks into a single deposition process. By incorporating multiple dyes into one emitter layer that is deposited in a single step, the need for multiple precise alignment operations is eliminated, thereby dramatically reducing the manufacturing precision requirements while still achieving full-color display capability.
3Illumination intensity
If multiple deposition steps with shadow masks are used, then color saturation can be optimized, but dust generation and process inefficiency increase
Solution Approach 1:
The patent combines multiple dye materials into a single deposition step, creating one emitter layer that contains all necessary color-emitting components. This approach eliminates the repeated opening and closing of vacuum chambers and the repeated insertion/removal of shadow masks, thereby reducing dust generation from the environment while maintaining color saturation through optimized dye placement and concentration within the single layer.
4Measurement precision
If separate layers with different thicknesses are deposited to achieve different colors, then color accuracy is improved, but the number of deposition steps and overall process time increase
Solution Approach 1:
The patent segments the emitter layer into different regions or depth zones, each containing dyes with specific emission characteristics. By controlling the spatial distribution and concentration of different dyes within a single layer deposited in one step, the invention achieves precise color accuracy without requiring multiple sequential deposition steps, thereby significantly reducing the overall process time.
Solution Approach 2:
The invention merges the functionality of multiple separately deposited layers into a single composite emitter layer. This single layer contains multiple dyes positioned and concentrated to achieve the desired color accuracy, eliminating the need for multiple deposition steps and reducing the total process time while maintaining or improving color precision.
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 approach simplifies the production of OLEDs by enabling the generation of various colors in a single work step, improving color accuracy and efficiency, and allowing for the creation of displays and light sources with enhanced color rendering and reduced complexity, suitable for both display and sensor technology applications.
Implementation Method 1
an optical resonator consisting of two reflective layers 2, 7 for reflecting light, in which a standing wave forms if the optical path length of the resonator is a multiple of the wavelength of the emitted light
Implementation Method 2
a lossy optical resonator consisting of two reflective layers 2, 7 for reflecting light
Implementation Method 3
a layer 4 which has been structured photolithographically and which consists of photochemically crosslinkable materials
Data Source
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AI summary
The invention relates to an organic light-emitting diode, known under the abbreviation OLED, and to a method for the production of such an organic light-emitting diode. According to the invention, an OLED or organic light-emitting diode having an emitter layer (5) is produced, said emitter layer emitting white light in particular. The emitter layer (5) is arranged within a lossy, optical resonator. The optical path length between the two reflecting layers of the resonator determines the color of the light emitting from the optical resonator and, consequently, from the light-emitting diode. In order to be able to create a variety of colors, there must be different optical path lengths between the two reflecting surfaces. The correspondingly different distances can be produced in only one work step, in contrast to the prior art, by a photolithographic method. The result is an organic light-emitting diode having a lossy optical resonator, having an emitter layer (5) and a layer (4) that can be photolithographically structured. Said layer (4) is comprised of photochemically curable materials. Organic light-emitting diodes according to the invention can be used in light sources, lighting, sensors or spectrometers.