OLED Manufacturing via Hole Function Layer Melting
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Solution Overview
Problem
The existing manufacturing methods for organic light emitting devices (OLEDs) face challenges in achieving improved interfacial characteristics between electrodes and organic layers, which affect the lifespan and efficiency of the devices.
Innovation Solution
A method involving the formation of a hole function layer and a first emission layer, followed by heat treatment to improve interfacial bonding and eliminate moisture, along with the use of specific materials and layers for efficient electron and hole transport, including a second emission layer with a host and dopant for light emission, and a thin electron transportation and injection layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional manufacturing methods are used for OLEDs, then the manufacturing process is simple, but the interfacial characteristics between electrodes and organic layers are insufficient
Solution Approach 1:
The hole function layer is divided into multiple sub-layers with different materials and functions. The first sub-layer (hole injection layer) uses HIL material, the second sub-layer (hole transportation layer) uses HTL material, and the third sub-layer (buffer layer) uses buffer material. This segmentation allows each sub-layer to optimize its interfacial characteristics with adjacent layers, resolving the contradiction between improving interfacial reliability and maintaining manufacturing simplicity.
Solution Approach 2:
Different sub-layers within the hole function layer are designed with locally optimized material compositions and thicknesses. The hole injection layer is optimized for electrode interface, the hole transportation layer for organic emission layer interface, and the buffer layer for intermediate interface. This local quality approach improves overall interfacial characteristics without requiring complete redesign of the entire manufacturing process.
2Duration of action of stationary object
If moisture is present in organic layers, then the manufacturing process is simpler without additional treatment, but the OLED lifespan is reduced
Solution Approach 1:
The heat treatment step is performed as a preliminary action before final device assembly and testing. This heat treatment eliminates moisture from the organic layers and improves interfacial characteristics in advance, preventing lifespan reduction issues before they occur. By performing this moisture elimination step early in the manufacturing process, the patent maintains ease of manufacture while achieving extended OLED lifespan.
Solution Approach 2:
The patent converts the potentially harmful effect of moisture presence into a beneficial process by using controlled heat treatment. The heat treatment transforms the moisture elimination from a complex additional process into an integrated step that simultaneously achieves moisture removal, interface improvement, and material stabilization, thereby extending lifespan without significantly complicating manufacturing.
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 the interface characteristics between electrodes and organic layers, leading to improved OLED lifespan and efficiency, with specific examples showing increased lifespan and maintained luminous efficiency compared to comparative examples.
Implementation Method 1
heat treatment to improve interfacial bonding and eliminate moisture
Implementation Method 2
Holes supplied from the first electrode and electrons supplied from the second electrode bond together in the light emitting layer to form excitons, and the OLED emits light due to energy generated when the excitons return to the bottom level
Data Source
Figure 1~2B
Figure 2C
AI summary
An organic light emitting device and a method for manufacturing the same are provided. The organic light emitting device comprises: a substrate (110); a first electrode (120) disposed on the substrate; a hole function layer (130) disposed on the first electrode; a first emission layer (141) disposed on the hole function layer; a second emission layer (142) disposed on the first emission layer; an electron function layer (150) disposed on the second emission layer; and a second electrode (170) disposed on the electron function layer, wherein the hole function layer (130) and the first emission layer (141) are melted.