OLED Charge Generation Layer Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic light-emitting diodes (OLEDs) with charge generation layers (CGLs) face efficiency losses due to absorption of emitted light by CGLs and high costs of commercial p- and n-dopants, while also experiencing temperature-dependent voltage instability.
Innovation Solution
The organic light-emitting component incorporates at least two organic light-emitting layers that also function as p- and/or n-layers in a charge generation layer, eliminating the need for commercial dopants and simplifying the OLED construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If charge generation layers (CGLs) are used between emitter layers to generate multiple photons per charge carrier pair, then light emission efficiency is improved, but absorption of emitted light by CGLs reduces overall efficiency
Solution Approach 1:
The patent extracts the charge generation function from the dedicated CGL layers and integrates it into the emitter layers themselves. The emitter layers are designed to perform both light emission and charge generation functions, eliminating the need for separate CGL layers that would absorb emitted light.
Solution Approach 2:
The patent merges the charge generation layer function with the emitter layer function. The emitter layers are constructed to serve dual purposes: generating light through electroluminescence and generating charge carriers through their p-n junction structure, thereby eliminating the need for separate CGL layers.
2Reliability
If conventional p- and n-dopants are used in charge generation layers, then charge carrier generation is achieved, but production costs increase due to expensive commercial dopants
Solution Approach 1:
The emitter layers are designed to be self-doping through their intrinsic p-n junction structure. The p-type and n-type regions are formed within the emitter layer materials themselves, eliminating the need for additional expensive commercial dopants while maintaining charge carrier generation capability.
3Reliability
If conductivity doping is applied in charge generation layers, then charge carrier generation is improved, but temperature-dependent voltage instability increases
Solution Approach 1:
The patent removes the conductivity doping approach from the emitter layers and instead relies on the intrinsic p-n junction structure to generate charge carriers. This eliminates the temperature-dependent voltage instability associated with doped layers while maintaining charge carrier generation through the junction's internal electric field.
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 enhances light emission efficiency by reducing absorption losses and lowers production costs, while also improving stability by reducing the number of layers and interfaces, leading to a more efficient and cost-effective OLED design.
Implementation Method 1
The organic functional layer stack comprises the at least two organic light-emitting layers in the form of organic electroluminescent layers, which generate light by charge carrier recombination during operation of the organic light-emitting component
Data Source
AI summary
An organic light-emitting component is disclosed. The component includes an organic functional layer stack between two electrodes, where the organic functional layer stack has at least two organic light-emitting layers and at least one charge generation layer, and where at least one of the at least two organic light-emitting layers is part of the charge generation layer.