Nano-diamondoid Cathode Interlayer for OLED Voltage Reduction

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Solution Overview

Problem

Organic light-emitting diodes (OLEDs) face challenges with short lifetimes and high driving voltage, which affect power efficiency and reliability, limiting their competitiveness with light-emitting diodes in general lighting markets and display applications.

Innovation Solution

Incorporating nano-diamondoids into the electronic structure of OLEDs, specifically using hydrogen-terminated or functionalized nano-diamondoids in organic functional layers to reduce driving voltage and enhance stability, thereby improving power efficiency and longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If conventional OLED structures are used, then device functionality is achieved, but driving voltage remains high and lifetime is short

Engineering Contradiction:
ImproveOLED lifetimeVSAvoiddriving voltage
Core Design Contradiction:
Duration of action of moving objectVSUse of energy by moving object

Solution Approach 1:

The patent introduces a cathode interlayer comprising diamondoid compounds as an intermediary between the cathode and the emissive layer. This interlayer mediates the interaction between the cathode and organic materials, improving electron injection efficiency and reducing driving voltage while enhancing device stability and lifetime.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical and physical parameters of the cathode interface by using diamondoid compounds with specific properties (negative electron affinity, high stability). This parameter change in the interlayer material enables lower driving voltage and improved device performance.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If doped cathodes are used to reduce driving voltage, then voltage is reduced, but reliability deteriorates due to reactivity and oxygen sensitivity

Engineering Contradiction:
Improvedriving voltageVSAvoidproduction reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces reactive, oxygen-sensitive dopants with stable diamondoid compounds that do not require strict inert atmosphere handling. The diamondoid interlayer provides stable electron injection without the reliability issues of doped cathodes.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The diamondoid compounds create a chemically stable, inert-like environment at the cathode interface, protecting against oxygen and moisture sensitivity that plagues doped cathodes, thereby improving production reliability.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Reliability

If LiF/Al or Ba/Al cathodes are used, then electron injection is improved for selected materials, but universality is lost

Engineering Contradiction:
Improveelectron injection efficiencyVSAvoidcathode universality
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent employs diamondoid compounds in the cathode interlayer that provide universal electron injection enhancement across different OLED configurations and emissive materials, replacing the material-specific nature of LiF/Al and Ba/Al cathodes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2462203B1Electronic devices comprising multi cyclic hydrocarbons
Publication Date: 2016.03.02 MERCK PATENT GMBH
  • EP2462203B1 patent drawingFigure 1~4
  • EP2462203B1 patent drawingFigure 5(a)~6(b)
  • EP2462203B1 patent drawing

AI summary

The present invention relates to compositions comprising functionalized or un-functionalized multi cyclic hydrocarbons and functional organic compounds, which can be used in different electronic devices. The invention further relates to an electronic device comprising one or more organic functional layers, wherein at least one of the layers comprises at least one functionalized or un-functionalized multi cyclic hydrocarbon. Another embodiment of the present invention relates to a formulation comprising functionalized or un-functionalized multi cyclic hydrocarbons, from which a thin layer comprising at least one functionalized or un-functionalized multi cyclic hydrocarbon can be formed.