OLED Panel Mobility Ratio Segmentation for Carrier Recombination
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Solution Overview
Problem
Existing organic light-emitting display panels have low recombination efficiency of electrons and holes, leading to high bias voltage requirements, low light-emitting efficiency, and short lifetimes.
Innovation Solution
The organic light-emitting display panel is designed with a first light-emitting layer having a hole mobility to electron mobility ratio of 102 or greater and a second light-emitting layer with an electron mobility to hole mobility ratio of 102 or greater, optimizing the combination efficiency of electrons and holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional organic light-emitting display panel structure is used, then the device can operate with basic functionality, but the recombination efficiency of electrons and holes is low, resulting in high bias voltage requirements
Solution Approach 1:
The light-emitting layer is divided into multiple sub-layers with different mobility ratios. The first light-emitting layer has a hole mobility to electron mobility ratio of 10^-2 to 10^-1, while the second light-emitting layer has an electron mobility to hole mobility ratio of 10^-2 to 10^-1. This segmentation allows different regions to optimize for different carrier types, improving overall recombination efficiency and reducing bias voltage requirements.
Solution Approach 2:
Different regions of the light-emitting layer are assigned different material compositions and mobility characteristics. The first light-emitting layer uses materials optimized for hole transport, while the second light-emitting layer uses materials optimized for electron transport. This local quality optimization ensures that each region contributes maximally to the overall device performance.
2Productivity
If a conventional organic light-emitting display panel structure is used, then the device can function, but the light-emitting efficiency is low
Solution Approach 1:
The light-emitting layer is segmented into multiple sub-layers with different mobility ratios to optimize recombination events. This segmentation increases the probability of radiative recombination while reducing non-radiative losses, thereby improving light-emitting efficiency and reducing energy loss.
Solution Approach 2:
The mobility ratio parameter is changed across different light-emitting layers to optimize performance. By controlling the hole mobility to electron mobility ratio in the first layer and the electron mobility to hole mobility ratio in the second layer, the device achieves better balance between electron and hole injection, leading to improved light-emitting efficiency.
3Duration of action of stationary object
If a conventional organic light-emitting display panel structure is used, then the device can operate, but the lifetime is very short
Solution Approach 1:
The light-emitting layer is divided into multiple sub-layers with different mobility ratios to improve carrier balance. This segmentation reduces the formation of space charge regions and minimizes degradation mechanisms, thereby extending device lifetime while improving combination efficiency.
Solution Approach 2:
Different regions of the light-emitting layer are optimized for different carrier types, with the first layer favoring hole transport and the second layer favoring electron transport. This local quality optimization ensures balanced carrier injection and reduces stress on any single region, extending overall device lifetime.
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 configuration lowers the required bias voltage, enhances light-emitting efficiency, and prolongs the lifetime of the organic light-emitting display panel.
Implementation Method 1
electrons and holes are recombined to generate excitons. The excitons are unstable, and energy can be released. The energy is transferred to the molecules of the organic light-emitting material in the light-emitting layer, so that the molecules transit from a ground state to an excited state. The excited state is very unstable, and thus the excited molecules return to the ground state from the excited state, so that a light emitting phenomenon appears due to radiative transition
Data Source
AI summary
An organic light-emitting display panel and an organic light-emitting display device are provided. The organic light-emitting display panel includes: a first electrode, a first light-emitting layer, a second light-emitting layer and a second electrode that are stacked in turn. The ratio of the hole mobility to the electron mobility of the first light-emitting layer is greater than or equal to 102, and the ratio of the electron mobility to the hole mobility of the second light-emitting layer is greater than or equal to 102.