OLED Carrier Conversion Layer for Injection Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional organic light-emitting diodes face challenges in maintaining long service lifetime and integration with other components due to the need for low work function materials, which compromise light transmittance and carrier injection efficiency over time.
Innovation Solution
Incorporating a carrier conversion layer between the electrodes and organic material layers, allowing for the use of high work function materials and enabling flexible electrode material selection, thereby improving carrier injection efficiency and service lifetime without the limitations of low work function materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low work function materials are used to improve electron injection efficiency, then carrier injection efficiency is improved, but light transmittance is reduced and service lifetime is reduced
Solution Approach 1:
The patent introduces a carrier conversion layer as an intermediary between the electrode and the organic material layer. This layer converts carriers from the electrode into carriers suitable for the organic material layer, enabling the use of high work function materials (which have longer service lifetime and better light transmittance) while still achieving effective carrier injection into the organic material layer.
2Reliability
If low work function materials are used to improve electron injection efficiency, then carrier injection efficiency is improved, but material selection is limited and integration difficulty increases
Solution Approach 1:
The carrier conversion layer acts as a mediator that decouples the electrode material selection from the requirements of the organic material layer. This allows designers to choose from a broader range of electrode materials (including high work function materials like ITO, IZO, and various metals) without being constrained by the need for low work function materials, thereby improving adaptability and ease of integration with other components.
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
The solution enhances carrier injection efficiency and extends the service lifetime of organic light-emitting diodes, facilitating easier integration with other components and maintaining luminous efficiency, as demonstrated by improved performance metrics compared to conventional approaches.
Implementation Method 1
a carrier conversion layer which may be interposed between the first electrode and the hole transport layer or between the second electrode and the electron transport layer
Implementation Method 2
An organic light-emitting diode (OLED) is a self-luminous light-emitting device... electrons and holes are injected from the cathode and the anode respectively, and recombine in the organic material layer to emit light
Data Source
AI summary
The present invention relates to an organic light emitting diode, comprising: a first electrode; an organic material layer which comprises a hole transport layer, an electron transport layer and an light emitting layer, wherein the hole transport layer may be interposed between the first electrode and the light emitting layer, and the light emitting layer may be interposed between the hole transport layer and the electron transport layer; a second electrode which is disposed on the organic material layer; and a carrier conversion layer which may be interposed between the first electrode and the hole transport layer or between the second electrode and the electron transport layer; wherein the carrier conversion layer has a thickness of 10 nm to 200 nm.