OLED Blocking Layer Electron Mobility Balance
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Solution Overview
Problem
The lifetime of Organic Light Emitting Diode (OLED) displays is shortened due to excess electrons not being recombined, leading to degradation of film layers and interfaces, as materials trending towards electron transport prioritize electron transport efficiency over balance with hole transport.
Innovation Solution
Incorporating blocking layers with specific electron mobility characteristics and volume ratios of different materials between the light emitting layer and electrodes, balancing electron and hole transport to prevent excess carrier accumulation and reduce degradation, while maintaining high light emitting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If materials trending towards electron transport are employed as the light emitting layer material, then light emitting efficiency is improved, but OLED lifetime is shortened
Solution Approach 1:
The patent introduces blocking layers as intermediary structures between the light emitting layer and electrodes. These blocking layers mediate the carrier transport process by selectively blocking excess electrons while allowing holes to reach the light emitting layer, thereby preventing carrier imbalance without compromising light emitting efficiency
Solution Approach 2:
The patent modifies the electron mobility parameter of blocking layer materials to specific ranges (1.0×10^-6 to 1.0×10^-5 cm2/(V·s) for first blocking material, 1.0×10^-5 to 1.0×10^-4 cm2/(V·s) for second blocking material). This parameter optimization enables the blocking layers to effectively regulate carrier transport, balancing electron and hole injection to extend OLED lifetime while maintaining high light emitting efficiency
2Speed
If electron transport efficiency is prioritized, then electron transport performance is improved, but carrier balance is disrupted leading to film layer degradation
Solution Approach 1:
The blocking layers are positioned to preemptively block excess electrons before they can reach and damage the film layers and interfaces. By applying this preliminary anti-action, the patent prevents the harmful effects of carrier imbalance on film layer stability
Solution Approach 2:
The blocking layers are constructed from composite materials with different electron mobility characteristics. The first blocking material (lower electron mobility) and second blocking material (higher electron mobility) work synergistically to provide graded carrier blocking, effectively protecting film layers while maintaining overall device performance
Data Source
AI summary
Provided are an OLED, display panel and display device. The OLED includes a first electrode, a second electrode, a light emitting layer and at least one blocking layer. The second electrode is arranged opposite to the first electrode. The light emitting layer is arranged between the first electrode and the second electrode. The blocking layer is arranged between the light emitting layer and the second electrode and/or between the light emitting layer and the first electrode. Each blocking layer of the at least one blocking layer comprises at least two blocking materials, electron mobility of at least one blocking material of the at least two blocking materials is lower than a first preset value, electron mobility of at least another blocking material of the at least two blocking materials is higher than a second preset value, and the first preset value is lower than the second preset value.