Cyclic Guanidine Organic Compound for Lithography Electron Injection

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Solution Overview

Problem

Current methods for forming high-resolution organic light-emitting devices using lithography face challenges with alkali metal compounds, leading to increased driving voltage and reduced current efficiency due to exposure to oxygen and water, especially in tandem light-emitting devices where intermediate layers are affected.

Innovation Solution

An organic compound with a cyclic guanidine skeleton, preferably including an imidazole ring, is used for the electron-injection or intermediate layer, offering low water solubility and preventing degradation, thus replacing alkali metals and maintaining device characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If alkali metal compounds are used for electron-injection layer to reduce driving voltage, then voltage is reduced, but driving voltage increases and current efficiency decreases due to exposure to oxygen and water during lithography processing

Engineering Contradiction:

Improvedriving voltageVSAvoidcurrent efficiency

Core Design Contradiction:

Use of energy by stationary objectVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter by replacing alkali metal compounds with organic compounds containing cyclic guanidine skeletons. This new material class maintains low work function for electron injection while being chemically stable against oxygen and water exposure during lithography processing, thus resolving the contradiction between low driving voltage and high current efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material design by combining cyclic guanidine skeleton with aromatic hydrocarbon groups or heteroaromatic groups. This composite structure provides both the electron-injection capability (from cyclic guanidine) and chemical stability (from aromatic groups), preventing degradation during processing while maintaining low driving voltage

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If lithography method is used to form finer patterns, then resolution is improved, but alkali metal compounds are exposed to oxygen and water causing increased driving voltage and reduced current efficiency

Engineering Contradiction:

Improvepattern resolutionVSAvoiddevice characteristics

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces the fragile alkali metal compounds that degrade during processing with robust organic compounds containing cyclic guanidine skeletons. These new materials can withstand the lithography processing environment (exposure to oxygen and water) without significant degradation, thus enabling high-resolution patterning while maintaining stable device characteristics

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent creates a chemically inert environment by using organic compounds with cyclic guanidine skeletons that are resistant to oxidation and hydrolysis during lithography processing. This protects the electron-injection layer from environmental degradation while allowing the lithography process to proceed, thus achieving both high resolution and maintained device performance

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

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 organic compound with a cyclic guanidine skeleton enhances electron-injection properties and reduces solubility in water, maintaining favorable light-emitting device characteristics and efficiency, even when processed using lithography methods.

Implementation Method 1

Carrier injection, especially electron injection into the organic compound layer, through which electricity is difficult to flow, has to overcome a high energy barrier

Methodology Applied

Scientific EffectElectron injection:

Implementation Method 2

energy generated by recombination of carriers (holes and electrons) injected to the organic compound layer from the electrodes causes light emission

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS20230348477A1Organic compound, light-emitting device, light-emitting apparatus, and electronic device

Publication Date: 2023.11.02 SEMICON ENERGY LAB CO LTD

AI summary

An electron-injection organic compound with low solubility in water is provided. An organic compound represented by General Formula (G1) is provided. In the organic compound, Ar represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms forming a ring or a substituted or unsubstituted heteroaromatic hydrocarbon group having 2 to 30 carbon atoms forming a ring, each of R1 and R2 independently represents hydrogen (including deuterium), an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 13 carbon atoms forming a ring, n represents an integer greater than or equal to 1 and less than or equal to 6, and L is the group represented by General Formula (L-1). In General Formula (L-1), each of R3 and R4 independently represents hydrogen (including deuterium) or an alkyl group having 1 to 6 carbon atoms, and k is an integer greater than or equal to 1 and less than or equal to 5.