Organic Light Emitting Device With Intermediate Layer
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Solution Overview
Problem
Existing organic light emitting devices face challenges in achieving high light emission efficiency and long lifespan due to the overlap configuration of light-emitting layers, which affects the injection and transport of holes and electrons.
Innovation Solution
The organic light emitting device incorporates two light-emitting layers with an intermediate layer in between, along with specific hole and electron transport regions to optimize the overlap configuration, ensuring efficient injection and transport of charge carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If two light-emitting layers are disposed to overlap with each other to increase light emission efficiency, then light emission efficiency is improved, but stress accumulation and charge carrier injection problems occur
Solution Approach 1:
An intermediate layer is introduced between the first and second light-emitting layers to act as a mediator. This intermediate layer includes a hole blocking region that prevents holes from the first light-emitting layer from directly interacting with the second light-emitting layer, thereby reducing stress accumulation while maintaining the overlapping configuration for high light emission efficiency.
Solution Approach 2:
The device is segmented into distinct functional regions: the first light-emitting layer, the intermediate layer with hole blocking region, and the second light-emitting layer. This segmentation allows each layer to perform its specific function independently, preventing charge carrier mixing and reducing stress while maintaining efficient light emission from both layers.
2Productivity
If light-emitting layers are overlapped to improve efficiency, then light emission efficiency is improved, but charge carrier injection and transport become complex
Solution Approach 1:
The intermediate layer serves as a mediator that simplifies charge carrier management. The hole blocking region within the intermediate layer clearly defines the boundaries of charge carrier flow, making the injection and transport processes more predictable and controllable despite the overlapping layer configuration.
Solution Approach 2:
Different regions of the device are assigned different functional qualities: the hole transport region is optimized for hole injection into the first light-emitting layer, while the electron transport region is optimized for electron injection into the second light-emitting layer. The intermediate layer's hole blocking region locally prevents hole diffusion into the second layer, creating clear functional zones that simplify overall charge carrier management.
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 enhances light emission efficiency and extends the device's lifespan by reducing stress and improving charge carrier injection, resulting in a display with good afterimage characteristics.
Implementation Method 1
a hole transport region to inject/transport a hole from the anode into the first light-emitting part, the second light-emitting part, and the fourth light-emitting part
Implementation Method 2
a hole transport region to inject/transport a hole from the anode into the first light-emitting part, the second light-emitting part, and the fourth light-emitting part
Implementation Method 3
an electron transport region to inject/transport an electron from the cathode into the second light-emitting part, the third light-emitting part, and the fourth light-emitting part
Implementation Method 4
an electron transport region to inject/transport an electron from the cathode into the second light-emitting part, the third light-emitting part, and the fourth light-emitting part
Implementation Method 5
a first light-emitting layer between the anode and the cathode, the first light-emitting layer including a first light-emitting part and a second light-emitting part
Data Source
AI summary
An organic light emitting device includes a first light-emitting layer between an anode and a cathode, the first light-emitting layer including a first light-emitting part and a second light-emitting part, a second light-emitting layer spaced apart from the first light-emitting layer and including a third light-emitting part and a fourth light-emitting part, the third light-emitting part overlapping the first light-emitting part and not overlapping the second light-emitting part, and the fourth light-emitting part not overlapping either of the first light-emitting part and the second light-emitting part, an intermediate layer between the first light-emitting layer and the second light-emitting layer, a hole transport region to inject/transport a hole into the first light-emitting part, the second light-emitting part, and the fourth light-emitting part, and an electron transport region to inject/transport an electron into the second light-emitting part, the third light-emitting part, and the fourth light-emitting part.