OLED Diffusion Layer Fills Traps to Reduce Joule Heating
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Solution Overview
Problem
Organic light emitting diodes (OLEDs) face challenges with short lifetime and poor luminous performance due to carrier trapping and joule heating effects, which are difficult to address through material improvements given the lengthy development process and low yield of new emitting materials.
Innovation Solution
Incorporating a diffusion layer with both organic and inorganic parts between functional layers in the OLED structure, where the diffusion layer dissociates and diffuses metal ions to fill traps in adjacent layers, reducing joule heating and enhancing carrier release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If new emitting materials are developed to improve OLED performance, then luminous performance and lifetime can be enhanced, but the development period is long and the yield of material is low making it difficult to achieve mass production
Solution Approach 1:
The invention segments the OLED structure into multiple functional layers (hole injection layer, hole transport layer, emission layer, electron transport layer, electron injection layer) with diffusion layers positioned between adjacent functional layers. This segmentation allows independent optimization of each layer's properties and enables mass production through standardized layer fabrication processes, resolving the contradiction between improving lifetime and maintaining productivity.
Solution Approach 2:
The invention employs composite materials in the diffusion layers that contain both organic components and inorganic metal ions. These composite diffusion layers simultaneously provide trap-filled metal ions to improve lifetime and maintain compatibility with existing manufacturing processes, thus enhancing reliability without sacrificing productivity.
2Reliability
If carriers are trapped in deep traps of organic materials, then joule heating effect increases and molecular bonds break, but improving material purity and structure is time-consuming and reduces production yield
Solution Approach 1:
The invention applies preliminary action by incorporating diffusion layers during the manufacturing process that proactively release metal ions to fill traps before carriers can become trapped and cause damage. This preventive approach improves OLED stability without requiring lengthy material purification processes, thereby maintaining mass production efficiency.
Solution Approach 2:
The diffusion layers act as intermediary components between adjacent functional layers, mediating the interaction between carriers and traps by providing metal ions that fill traps. This intermediary approach stabilizes the OLED structure and prevents molecular bond breaking while maintaining compatibility with existing manufacturing processes.
3Productivity
If carriers are released from traps through joule heating, then carriers can continue to emit light, but excessive joule heating causes molecular bond breaking and reduces OLED lifetime
Solution Approach 1:
The invention changes the physical-chemical parameters of the OLED structure by introducing diffusion layers with specific metal ion concentrations and distributions. These parameter changes enable trap filling that reduces joule heating effects while maintaining light emission efficiency, thus resolving the contradiction between productivity and reliability.
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 effectively extends the lifetime and improves luminous performance of OLEDs by eliminating traps and reducing joule heating, leading to a more stable and efficient light-emitting diode.
Implementation Method 1
the diffusion layer dissociates metal ions, the metal ions is diffusing to the functional layer adjacent to the diffusion layer
Implementation Method 2
the metal ions is diffusing to the functional layer adjacent to the diffusion layer for filling traps
Implementation Method 3
the electrodes and holes are respectively injected by cathode and anode, and transfer to the emission layer, and composited to exciton in the emission layer, and the exciton emitting by radiative transfer
Implementation Method 4
the exciton emitting by radiative transfer
Implementation Method 5
the carriers bonded by the shallow trap could be released by joule heating effect
Data Source
AI summary
An OLED and a display device has OLED are provided. The OLED includes an anode; an organic emission layer positioned on the anode, the organic emission layer includes a multilayer functional layer; a diffusion layer is positioned between at least two adjacent functional layers of the multilayer functional layer, the diffusion layer dissociates metal ions, the metal ions is diffusing to the functional layer adjacent to the diffusion layer for filling traps of the functional layer which is adjacent to the diffusion layer. The OLED of this invention could fill traps of the organic molecular materials, and decreases joule heating effect which generated by getting rid of the carriers bonded by traps. Therefore, it achieves to enhance life time and luminous performance of OLED.