OLED Panel Dual-Layer Host Material Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic electroluminescent devices face reduced efficiency and service life due to holes and electrons failing to excite light emission, with excitons diffusing to non-emitting regions and the light-emitting center position shifting, causing brightness and color variance.
Innovation Solution
An organic light-emitting display panel with two light-emitting material layers, each containing P-type and N-type host materials, where the P-type host material content exceeds N-type in the first layer and vice versa in the second layer, to balance carrier transport and control the recombination region, enhancing light-emitting efficiency and service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light-emitting layer is used, then the device structure is simple, but the light-emitting efficiency is reduced due to exciton diffusion to non-emitting regions
Solution Approach 1:
The light-emitting layer is divided into multiple sub-layers (first light-emitting material layer and second light-emitting material layer) with different host material compositions. This segmentation creates distinct regions for hole and electron transport, confining excitons within the light-emitting layers and preventing diffusion to non-emitting regions, thereby improving light-emitting efficiency.
Solution Approach 2:
Different regions of the light-emitting layer are assigned different material compositions: the first light-emitting material layer contains P-type host material with higher content for hole transport, while the second light-emitting material layer contains N-type host material with higher content for electron transport. This local quality differentiation optimizes carrier transport and recombination in each region.
2Reliability
If holes and electrons traverse the light-emitting layer to the electrodes, then carrier transport is achieved, but energy is lost without light emission and device service life is reduced
Solution Approach 1:
The light-emitting layer is segmented into multiple sub-layers with different host material compositions to create distinct transport channels. This segmentation ensures that holes and electrons are transported and recombined within the light-emitting layers rather than traversing to the electrodes, converting potential energy loss into useful light emission and extending device service life.
Solution Approach 2:
The multi-layer light-emitting structure acts as an intermediary between the electrodes, providing controlled carrier transport and recombination zones. This intermediary structure prevents direct carrier traversal to electrodes, ensuring that carrier recombination occurs within the light-emitting materials where it can produce photons.
3Device complexity
If the light-emitting center position is allowed to shift, then the device structure is simple, but brightness and color variance occur in the display panel
Solution Approach 1:
The light-emitting layer is segmented into multiple sub-layers with different host material compositions, creating a structured configuration that stabilizes the light-emitting center position. This segmentation prevents random shifts by providing defined regions for carrier recombination, ensuring consistent brightness and color across the display panel.
Solution Approach 2:
Different regions of the light-emitting layer are assigned specific material compositions optimized for their functions, creating a stable and predictable carrier recombination pattern. This local quality differentiation ensures that the light-emitting center remains positioned where intended, preventing brightness and color variance.
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 effectively restricts the recombination region, improves light-emitting efficiency, and stabilizes brightness and color, reducing carrier diffusion and triplet-triplet annihilation, thereby extending device life and maintaining consistent performance.
Implementation Method 1
An organic light-emitting diode (OLED), also called an organic electroluminescent device, is a phenomenon that when driven by an electric field, the light-emitting material emits light via injection and recombination of carriers
Implementation Method 2
When voltages are applied to the anode and the cathode, holes and electrons are transported and moved to the light-emitting layer, respectively
Implementation Method 3
the holes and the electrons are recombined in the light-emitting layer to generate excitons
Implementation Method 4
The excitons migrate under the effect of the electric field, transfer the energy to the light-emitting material, and excite electrons in the light-emitting material
Implementation Method 5
Via radiation, the excited state deactivates to generate photon, thus emitting light
Implementation Method 6
The first light-emitting material layer includes at least one P-type host material and at least one N-type host material, and a total volume percentage content of the P-type host material is more than a total volume percentage content of the N-type host material
Data Source
AI summary
An organic light-emitting display panel and an electronic device thereof are provided. The organic light-emitting display panel comprises a substrate, and a first electrode, a first light-emitting material layer, a second light-emitting material layer, and a second electrode disposed above the substrate in a preset order. The first light-emitting material layer includes at least one P-type host material and at least one N-type host, material, and a total volume percentage content of the P-type host material is more than a total volume percentage content of the N-type host material. The second light-emitting material layer includes at least one P-type host material and at least one N-type host material, and a total volume percentage content of the N-type host material is more than a total volume percentage content of the P-type host material.