Phase-Transition Optical Isomer for Transparent EL Electrode Patterning
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Solution Overview
Problem
Conventional transparent electroluminescent (EL) display devices face challenges in maintaining transmittance due to the presence of a second electrode in transparent areas, requiring complex masking processes that increase production costs and limit patterning size.
Innovation Solution
A phase-transition optical isomer compound is used in the electron auxiliary layer, allowing for selective deposition of a conductive material without a masking process, ensuring the second electrode is only formed in emission areas and not in transparent areas, thereby preventing transmittance decrease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a second electrode is formed in transparent areas to complete the EL display device structure, then device functionality is improved, but transmittance decreases
Solution Approach 1:
The patent applies local quality by forming the second electrode only in specific regions (emission areas) while leaving other regions (transparent areas) electrode-free. This is achieved through region-specific deposition processes that consider local functional requirements: emission areas need electrodes for EL operation, while transparent areas prioritize light transmission. The result is a spatially differentiated structure that optimizes both functionality and transmittance in different zones.
2Illumination intensity
If a masking process is used to remove the second electrode from transparent areas to improve transmittance, then transmittance is improved, but device complexity and production cost increase
Solution Approach 1:
The patent applies preliminary action by designing the deposition process to directly form the second electrode only in required emission areas from the beginning, rather than forming it everywhere and then removing it. This preventive approach eliminates the need for subsequent masking, photoresist application, exposure, development, and etching steps. The electrode pattern is established in the initial deposition step itself, significantly simplifying the fabrication process.
3Illumination intensity
If a masking process is used to pattern the second electrode, then transmittance is improved, but production time and cost increase
Solution Approach 1:
The patent applies the extraction principle by removing the masking process entirely from the fabrication sequence. Instead of using photoresist layers, exposure systems, and etching tools to pattern the second electrode, the invention extracts only the essential deposition step that directly forms the electrode in the correct locations. This eliminates multiple time-consuming process steps and associated equipment requirements, thereby improving production efficiency and reducing costs.
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 enhances transmittance by eliminating the second electrode from transparent areas, simplifies the fabrication process, and reduces production costs by avoiding the need for masking steps.
Implementation Method 1
a phase-transition optical isomer compound which has a lowest unoccupied molecular orbital (LUMO) level of −2.6 to −2.1 eV and a highest occupied molecular orbital (HOMO) level of −6.2 to −6.0 eV
Implementation Method 2
perform a deposition process of a conductive material onto an entire surface of the electron auxiliary layer to form a second electrode corresponding to the emission area
Data Source
AI summary
A phase-transition optical isomer compound is described, a transparent EL display device including the phase-transition optical isomer compound and a method of fabricating the EL display device, where a phase of the phase-transition optical isomer compound is transited by light irradiation and a second electrode of the EL display device is selectively deposited without a masking process.