LED Electron Injection Layer with Lanthanide Perovskite
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Solution Overview
Problem
Conventional light emitting diodes face challenges with low emission efficiency and short lifespan due to high driving voltage requirements, particularly in high-temperature environments such as those encountered in automotive applications.
Innovation Solution
A light emitting diode (LED) design incorporating an electron injection layer with a lanthanide element, an alkali metal, and a halogen, where the lanthanide element has a work function of 2.7 eV or less, and the electron injection layer comprises a perovskite structure, enhancing electron injection and mobility, thereby reducing the driving voltage and improving lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional electron injection layers are used, then the device structure is simple, but the emission efficiency is low and lifespan is short due to high driving voltage
Solution Approach 1:
The electron injection layer uses a composite material consisting of a lanthanide element (Yb, Sm, or Eu) combined with an alkali metal (K, Rb, or Cs) and a halogen (Cl, Br, or I) in a perovskite structure. This composite approach enables low work function (2.7 eV or less) for efficient electron injection, resolving the contradiction between emission efficiency and material complexity by creating a highly effective composite electron injection layer.
Solution Approach 2:
The invention changes the work function parameter of the electron injection layer to 2.7 eV or less by selecting specific lanthanide elements and their combinations with alkali metals and halogens. This parameter optimization enables efficient electron injection at lower driving voltages, improving emission efficiency while maintaining reasonable device complexity.
2Reliability
If high driving voltage is applied, then electron injection is sufficient, but the lifespan decreases particularly in high-temperature environments
Solution Approach 1:
By changing the work function parameter to 2.7 eV or less through the use of lanthanide-based perovskite materials, the invention enables efficient electron injection at reduced driving voltages. This parameter optimization directly addresses the contradiction by allowing sufficient electron injection without requiring high driving voltage, thereby extending lifespan especially in high-temperature automotive applications.
Solution Approach 2:
The invention uses readily available lanthanide elements (Yb, Sm, Eu), alkali metals (K, Rb, Cs), and halogens (Cl, Br, I) to create an electron injection layer that provides long-lasting performance. The perovskite structure of these common materials delivers stable, low-work-function characteristics that extend device lifespan without requiring expensive or rare materials.
3Productivity
If the electron injection layer contains lanthanide element, alkali metal, and halogen in perovskite structure, then electron injection efficiency is enhanced and driving voltage is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The invention specifies a work function parameter of 2.7 eV or less as the key performance criterion, allowing flexibility in the exact composition ratios of lanthanide elements, alkali metals, and halogens. This parameter-based approach enables manufacturers to achieve the desired electron injection efficiency through various compositional variations, reducing the stringency of manufacturing precision requirements while maintaining high electron injection efficiency.
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 proposed LED design significantly increases light emission efficiency and extends lifespan by reducing the driving voltage, maintaining efficiency and reliability even in high-temperature conditions.
Implementation Method 1
an electron injection layer between the second electrode and the emission layer, wherein the electron injection layer comprises a lanthanide element, a first element, and a second element... the electron injection layer comprises a perovskite structure, enhancing electron injection and mobility
Implementation Method 2
the lanthanide element has a work function of 2.7 eV or less
Data Source
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AI summary
A light emitting diode and a light emitting diode display, the light emitting diode comprising: a first electrode (120); a second electrode (190) overlapping the first electrode (120); an emission layer (150) between the first electrode (120) and the second electrode (190); and an electron injection layer (180) between the second electrode (190) and the emission layer (150), wherein the electron injection layer (180) comprises a lanthanide element, a first element, and a second element, and wherein the first element is an alkali metal and the second element is a halogen, and the electron injection layer (180) comprises the first element and the second element in an amount of 1 vol% to 20 vol%, based on a total volume of a material comprising the lanthanide element, the first element, and the second element.