Organic Light Emitting Device P Doping Charge Generating Layer
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Solution Overview
Problem
The existing organic light emitting devices that emit white light require multiple deposition processes, leading to an increased driving voltage due to the separate formation of N type and P type charge generating layers and hole transporting layers.
Innovation Solution
The solution involves forming a P doping charge generating layer and a layer with hole transporting characteristic using the same organic material, where the P doping charge generating layer is doped with a dopant, and these layers are alternately repeated, reducing the number of deposition processes and improving carrier mobility and electrical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate deposition processes are used for N type charge generating layer, P type charge generating layer, and hole transporting layer, then each layer can be formed with optimized properties, but the number of deposition processes increases and driving voltage increases
Solution Approach 1:
The patent combines the P type charge generating layer and the hole transporting layer into a single deposited layer. This layer contains both dopant molecules (providing P type charge generating capability) and host organic material (providing hole transporting capability). By merging these two previously separate layers into one, the number of deposition processes is reduced while maintaining the functional properties of both layers.
2Manufacturing precision
If multiple separate layers are deposited, then precise control of each layer's properties is achieved, but the driving voltage increases due to increased process complexity
Solution Approach 1:
The patent changes the parameters of the single deposited layer by controlling the dopant concentration and the ratio of dopant to host material. By adjusting these parameters, the layer simultaneously achieves P type charge generating properties and hole transporting properties, eliminating the need for multiple separate layers and reducing driving voltage.
3Reliability
If P type charge generating layer and hole transporting layer are formed separately, then interface characteristics can be optimized, but the number of interfaces increases and process complexity increases
Solution Approach 1:
The patent merges the P type charge generating layer and hole transporting layer into a single homogeneous layer deposited in one process. This eliminates the interface between these two layers, simplifying the manufacturing process while maintaining optimal charge generating and hole transporting characteristics throughout the layer.
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
This approach simplifies the deposition process, reduces the driving voltage, and enhances the interface characteristics between the charge generating and hole transporting layers, resulting in improved light emitting efficiency and brightness.
Implementation Method 1
the P doping charge generating layer is doped with a dopant
Implementation Method 2
electrons are injected into the cathode, and holes are injected into the anode. If the electrons generated in the cathode and the holes generated in the anode are injected into the organic light emitting portion, an exciton is generated by combination of the injected electrons and holes, and then the generated exciton is transited from the excited state to a ground state, whereby light is emitted
Data Source
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AI summary
An organic light emitting device comprises first and second electrodes; first and second stacks formed between the first electrode and the second electrode, the first and second stacks emitting their respective colors different from each other; and an intermediate layer formed between the first stack and the second stack, wherein the intermediate layer includes a first intermediate layer disposed to be adjacent to the first stack to provide electrons to the first stack, and a second intermediate layer disposed to be adjacent to the second stack to provide holes to the second stack, and the second intermediate layer includes a P doping charge generating layer formed on the first intermediate layer and a layer having hole transporting characteristic formed on the P doping charge generating layer.