OLED Buffer Element for Carrier Balance and Metal Blocking
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Solution Overview
Problem
OLEDs face inefficiencies due to low hole and electron transport rates and imbalance, as well as metal atom contamination from top electrodes, which reduce device efficiency and lifetime.
Innovation Solution
Incorporating a buffer element made of a mixture of P-type and N-type semiconductor materials between the electrodes to enhance carrier balance and transport performance, specifically using materials like copper phthalocyanine, pentacene, and molybdenum oxide, with a mixing ratio from 8:1 to 1:8, to improve the efficiency and longevity of OLED components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a multilayer structure with conventional layers is used, then the OLED can be constructed with standard components, but the hole transport rate and electron transport rate remain low and carrier balance is difficult to maintain
Solution Approach 1:
The patent introduces a buffer element as an intermediary layer between the electrode and the organic electroluminescence element. This buffer element contains both P-type semiconductor material (for hole transport) and N-type semiconductor material (for electron transport), acting as a mediator that simultaneously improves both carrier transport rates and maintains carrier balance, resolving the contradiction between productivity and reliability.
Solution Approach 2:
The buffer element is constructed using composite materials - a mixture of P-type semiconductor material and N-type semiconductor material. This composite structure enables the buffer element to provide both hole transport functionality (via P-type material) and electron transport functionality (via N-type material) within a single layer, thereby improving overall carrier transport rates while maintaining balance between electrons and holes.
2Reliability
If a metal top electrode is used, then the electrode provides good electrical conductivity, but metal atoms easily enter the electron transport layer during deposition and become exciton quenching centers
Solution Approach 1:
The buffer element serves as a protective intermediary layer between the metal top electrode and the organic electroluminescence element (specifically the electron transport layer). During the deposition process, this buffer layer prevents metal atoms from the electrode from penetrating into and contaminating the electron transport layer, thereby eliminating the harmful effect of metal atom-induced exciton quenching while preserving the electrical conductivity function of the metal electrode.
3Productivity
If the buffer element uses a mixture of P-type and N-type semiconductor materials, then carrier balance and transport performance are enhanced, but the device structure becomes more complex
Solution Approach 1:
The patent merges the functions of P-type semiconductor material (hole transport) and N-type semiconductor material (electron transport) into a single buffer element layer. By combining these two types of semiconductor materials in one element, the patent achieves enhanced carrier balance and transport performance without significantly increasing the overall device structure complexity, as the buffer element is integrated into the existing OLED architecture between the electrode and the organic electroluminescence element.
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 buffer element improves carrier balance and transport rates, increasing luminous efficiency, reducing metal ion quenching, and extending the device's lifespan by blocking metal atom contamination during deposition.
Implementation Method 1
the buffer element is made of a mixture of a P-type semiconductor material and an N-type semiconductor
Implementation Method 2
metal atoms can easily enter the electron transport layer and become an exciton quenching center during the deposition process
Data Source
AI summary
The present disclosure discloses an OLED component, comprising: a substrate, a bottom electrode arranged on the substrate, a top electrode opposite to the bottom electrode, and the top electrode spaced apart from the bottom electrode; an organic electroluminescence element arranged between the bottom electrode and the top electrode; at least one buffer element disposed between the top electrode and the organic electroluminescence element, and/or between the bottom electrode and the organic electroluminescence element, wherein the buffer element is configured to enhance carrier balance and, electrons transport performance and holes transport performance. The present disclosure enhances the luminous efficiency by the way of disposing the buffer element which is configured to enhance carrier balance, a electrons transport performance and holes transport performance between the top electrode and the organic electroluminescence element, and/or between the bottom electrode and the organic electroluminescence element.