Electron-Injection Layer Composition for Low-Voltage Light Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting elements face issues with high driving voltage, reduced emission efficiency, moisture sensitivity, oxidation, and crosstalk due to the use of alkali or alkaline earth metals in electron-injection layers, which also lead to reliability concerns and increased power consumption.
Innovation Solution
Incorporating a transition metal and an organic compound with an unshared electron pair to form a single occupied molecular orbital (SOMO) in the electron-injection layer, reducing the barrier to electron injection while enhancing moisture and oxidation resistance, and avoiding the use of alkali or alkaline earth metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If alkali or alkaline earth metals are used in the electron-injection layer to reduce the barrier to electron injection, then the driving voltage is reduced, but moisture resistance and oxidation resistance deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the electron-injection layer by replacing alkali/alkaline earth metals with transition metals having specific work functions (4.0-5.0 eV). This parameter change maintains the electron injection capability while improving moisture and oxidation resistance, as transition metals form more stable oxides and hydroxides compared to alkali metals.
Solution Approach 2:
The patent employs composite material strategies by combining transition metals with specific organic compounds in the electron-injection layer. This composite approach creates a material system that leverages the low work function of transition metals for electron injection while the organic components provide stability against moisture and oxidation, resolving the contradiction between power efficiency and reliability.
2Power
If alkali or alkaline earth metals are used in the electron-injection layer, then electron injection is facilitated, but crosstalk increases and reliability decreases
Solution Approach 1:
The patent changes the metal type parameter from alkali/alkaline earth metals to transition metals with controlled work functions (4.0-5.0 eV). This parameter change reduces crosstalk by preventing the excessive metal diffusion and interaction that occurs with alkali metals, while still maintaining efficient electron injection through the optimized work function range.
3Ease of manufacture
If conventional electron-injection layers are used, then manufacturing is straightforward, but emission efficiency is reduced and power consumption increases
Solution Approach 1:
The patent optimizes the work function parameter of the electron-injection layer by selecting transition metals within 4.0-5.0 eV. This parameter optimization enhances emission efficiency and reduces power consumption by improving electron injection efficiency, while the deposition process remains straightforward using conventional vacuum techniques.
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 results in a light-emitting element with lower driving voltage, improved moisture resistance, oxidation resistance, reduced power consumption, and higher reliability, along with reduced crosstalk and enhanced color purity.
Implementation Method 1
In recent years, research and development have been extensively conducted on light-emitting elements utilizing electroluminescence (EL). By application of a voltage between the electrodes of this element, light emission from the light-emitting material can be obtained.
Implementation Method 2
The first layer includes a transition metal and a first organic compound having an unshared electron pair. The first organic compound and the transition metal form single occupied molecular orbital (SOMO).
Data Source
AI summary
A reliable light-emitting element with low driving voltage is provided. The light-emitting element includes an electron-injection layer between a cathode and a light-emitting layer. The electron-injection layer is a mixed film of a transition metal and an organic compound having an unshared electron pair. An atom of the transition metal and the organic compound form SOMO.