Organic Light-Emitting Diode With Dual-Doped Single-Layer Architecture

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Solution Overview

Problem

Existing organic light-emitting diode structures require at least three different organic materials to fully exploit the advantages of doped layers, which increases complexity and cost, whereas structures with only two organic materials are electronically n- or p-doped on one side, limiting the benefits of doped layers.

Innovation Solution

An organic light-emitting diode with a cathode and an anode, featuring a first n-doped layer in contact with the cathode and a second p-doped layer in contact with the anode, where both layers include an electroluminescent zone that is neither n-doped nor p-doped, utilizing electronic dopants to facilitate charge injection and transport with high conductivity and reduced ohmic losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If three different organic materials are used in the diode structure, then the advantages of doped layers are fully exploited, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improveperformance of doped layersVSAvoidnumber of organic materials

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple organic material layers into a single organic layer with dual doping. Instead of using three separate layers (n-doped layer, electroluminescent layer, p-doped layer), the invention creates one organic layer that contains both n-doped zones and p-doped zones, thereby reducing device complexity while maintaining the performance benefits of doped layers

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single organic layer is designed to perform multiple functions simultaneously: it serves as the electroluminescent layer, the electron transport layer, and the hole transport layer through its different doped zones. This multi-functional design eliminates the need for separate specialized layers, resolving the contradiction between performance and complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If only two organic materials are used in the diode structure, then the production is simplified, but the benefits of doped layers are limited

Engineering Contradiction:

Improvenumber of organic materialsVSAvoidperformance of doped layers

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The organic layer exhibits different local properties through spatially distributed doping: n-doped zones near the cathode for electron injection, p-doped zones near the anode for hole injection, and undoped or differently doped regions for electroluminescence. This local differentiation allows the single-layer structure to achieve the functional performance previously requiring multiple layers

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the doping parameter (electron donor/acceptor concentration) within the single organic layer to create functionally distinct zones. By varying the doping level and type in different regions of the same layer, the structure achieves multiple functionalities without increasing material complexity

Inventive Principle:

Principle #35Parameter changes

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 simplifies production, enhances yield, and allows for efficient light extraction with high conductivity, using only two different organic layers, thereby reducing complexity and increasing efficiency while maintaining high performance.

Implementation Method 1

the carriers, i.e. electrons or holes, are therefore injected by a tunnel effect across a so-called 'depletion zone' lying in the doped zone in immediate proximity to the interface with the electrode i.e. cathode or anode

Methodology Applied

Scientific EffectTunnel effect:

Implementation Method 2

Methodology Applied

Scientific EffectTunnel effect:

Implementation Method 3

a first layer in contact with the cathode, based on a first organic material which is n-doped in a zone of this layer that is in contact with this cathode, a second layer in contact with the anode, based on a second organic material which is p-doped in a zone of this layer that is in contact with this anode, characterized in that said first layer and/or said second layer comprise an electroluminescent zone

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS8395313B2Light-emitting organic diode comprising not more than two layers of different organic materials

Publication Date: 2013.03.12 INTERDIGITAL CE PATENT HOLDINGS SAS

AI summary

The diode comprises:a first layer based on a first organic material, which is n-doped in a zone of this layer that is in contact with a cathode,a second layer based on a second organic material, which is p-doped in a zone of this layer that is in contact with an anode,and an electroluminescent zone which is incorporated in one of the layers and is in contact with the other layer, and which is neither n-doped nor p-doped.A high-yield diode is thus obtained in a particularly economical way.