Phosphine Oxide Matrix with Lithium Complex for OLED Cathode

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Solution Overview

Problem

Existing organic light-emitting diodes (OLEDs) face challenges in achieving high power efficiency and low operating voltage due to limitations in charge carrier injection and transport materials.

Innovation Solution

A semiconducting material comprising a compound with a phenylene spacer unit and a lithium complex is used as an electron transporting matrix and electrical dopant, respectively, to enhance charge transport and injection efficiency, thereby improving the electrical properties of OLEDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional organic materials are used in OLEDs, then the device structure is simple and manufacturing is easier, but power efficiency is low and operating voltage is high

Engineering Contradiction:
Improvepower efficiencyVSAvoidmaterial structure complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent employs composite materials by combining a phosphine oxide matrix with a lithium complex dopant to create an n-doped semiconducting material. This composite approach enables simultaneous improvement of electron mobility and charge carrier density, resolving the contradiction between power efficiency and material complexity by integrating multiple functional components into a unified semiconductor system.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies parameter changes by modifying the electrical properties of the organic semiconductor through chemical doping with lithium complex. This changes key parameters such as electron mobility, charge carrier density, and HOMO/LUMO energy levels, thereby improving power efficiency and reducing operating voltage without fundamentally altering the device structure.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If conventional organic materials are used in OLEDs, then manufacturing processes are simpler, but charge carrier injection and transport efficiency are insufficient

Engineering Contradiction:
Improvecharge transport efficiencyVSAvoidmanufacturing process complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent utilizes parameter changes through chemical doping to enhance charge transport efficiency. The lithium complex dopant modifies the electrical parameters of the phosphine oxide matrix, increasing electron mobility and charge carrier density. This approach improves productivity by enhancing charge transport without requiring complex manufacturing process changes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The lithium complex acts as an intermediary substance that facilitates charge carrier injection and transport within the organic semiconductor. By introducing this dopant mediator, the patent enhances charge transport efficiency while maintaining compatibility with existing OLED manufacturing processes, thus resolving the contradiction between productivity and ease of manufacture.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If conventional organic materials are used in OLEDs, then device structure is simpler, but operating voltage is high

Engineering Contradiction:
Improveoperating voltageVSAvoidsemiconducting material composition
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the energy levels and electrical conductivity of the organic semiconductor through lithium complex doping. This changes the HOMO and LUMO energy levels, reducing the energy barrier for charge injection and thereby lowering operating voltage. The approach resolves the contradiction by using chemical composition modification rather than structural complexity increase.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes mechanical/physical approaches with chemical mechanisms by using chemical doping to control electrical properties. Instead of relying on complex device structures or high applied voltages, the lithium complex dopant chemically modifies the semiconductor to achieve low-voltage operation, thereby resolving the contradiction between power and device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution results in OLEDs with improved power efficiency and reduced operating voltage, as demonstrated by comparative studies showing superior performance in both bottom and top emission structures.

Implementation Method 1

The lithium complex (II) works in the inventive semiconducting material as an electrical dopant

Methodology Applied
Scientific EffectElectrical doping: Dopants

Implementation Method 2

the compound of formula (I) has the function of a charge transporting matrix

Methodology Applied
Scientific EffectCharge transport: Conduction (electrical)

Implementation Method 3

the subsequent formation of excitons in a light emitting zone and the radiative recombination of those excitons

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3055891B1Semiconducting material comprising a phosphine oxide matrix and metal salt
Publication Date: 2024.10.30 NOVALED GMBH
  • EP3055891B1 patent drawingFigure 1~2
  • EP3055891B1 patent drawingFigure 3~4
  • EP3055891B1 patent drawingFigure 5~6

AI summary

The disclosure refers to a semiconducting material comprising a compound according to formula (I): wherein R1, R2 and R3 are independently selected from C1-C30-alkyl, C3-C30 cycloalkyl, C2-C30-heteroalkyl, C6-C30-aryl, C2-C30-heteroaryl, C1-C30-alkoxy, C3-C30- cycloalkyloxy, C6-C30-aryloxy, and from structural unit having general formula E-A-, wherein a is a phenylene spacer unit and E is an electron transporting unit that is selected from C10-C60 aryl and C6-C60 heteroaryl comprising up to 6 heteroatoms independently selected from O, S, P, Si and B and that comprises a conjugated system of at least 10 de localized electrons, at least one group selected from R1, R2 and R3 has the general formula E-A-, and at least one lithium complex having formula (II) wherein A1 is a C6-C30 arylene or C2-C30 heteroarylene comprising at least one atom selected from O, S and N in an aromatic ring and each of A2-A3 is independently selected from a C6-C30 aryl and C2-C30 heteroaryl comprising at least one atom selected from O, S and N in an aromatic ring. And an electronic device comprising a cathode, an anode and the semiconducting material according to any of claims 1-9 between the cathode and the anode. Furthermore, a compound and an electronic device are disclosed.