Organic Light-Emitting Device Insulating Film Thickness Optimization
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Solution Overview
Problem
In light-emitting devices with organic layers, interference fringes appear at the boundary between the light-emitting and peripheral regions due to the presence or absence of the insulating layer, affecting the visibility of surroundings when the device is not emitting light.
Innovation Solution
A light-emitting device structure featuring a light-emitting portion with a first and second electrode and an organic layer, along with a light-transmitting portion that includes the electrodes and a first layer between them, where an insulating film defines the light-emitting portion and is located in the light-transmitting portion, with a thin insulating film and a specific organic layer configuration to minimize interference fringes and electrical leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulating layer is used to define the light-emitting portion and reduce short circuit between electrodes, then electrical integrity is improved, but interference fringes appear at the boundary between light-emitting portion and periphery
Solution Approach 1:
The patent applies local quality by making the insulating film thickness non-uniform: a first insulating film with thickness of 1 nm to 10 nm is formed only in the light-transmitting portion (peripheral region), while the light-emitting portion has no insulating film or a different insulating structure. This localized differentiation eliminates interference fringes at the boundary while maintaining electrical insulation where needed.
Solution Approach 2:
The patent changes the thickness parameter of the insulating film from a uniform thick layer (conventional) to a thin non-uniform layer (1 nm to 10 nm) in the peripheral region. This parameter change reduces the optical path difference that causes interference fringes, while the film still provides sufficient electrical insulation.
2Reliability
If the insulating layer thickness is increased to prevent electrical leakage, then electrical insulation is improved, but the visibility of surroundings through the light-transmitting portion deteriorates
Solution Approach 1:
The patent optimizes the insulating film thickness parameter to a specific range (1 nm to 10 nm) in the light-transmitting portion. This thin thickness allows sufficient light transmission for good visibility while still providing adequate electrical insulation to prevent short circuits between electrodes.
Solution Approach 2:
The patent applies different insulating film thicknesses to different regions: a thin film (1 nm to 10 nm) in the light-transmitting portion for visibility, and either no film or a different insulating structure in the light-emitting portion. This spatial differentiation resolves the contradiction between insulation and visibility.
Data Source
AI summary
A light-emitting device (10) is, for example, a segment type display device, a display, or a lighting device, and includes a light-emitting portion (140), a light-transmitting portion (142), and an insulating film (150). The light-emitting portion (140) has a first electrode (110), an organic layer (120), and a second electrode (130). The light-transmitting portion (142) has the first electrode (110), the second electrode (130), and a first layer. The first layer is located between the first electrode (110) and the second electrode (130). In an example illustrated in the figure, the first layer is at least a part of the organic layer (120). The insulating film (150) defines the light-emitting portion (140) and is located in the light-transmitting portion (142).