Multi-nozzle OVJP for Graded OLED Emissive Layers
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Solution Overview
Problem
Traditional methods for manufacturing OLEDs with graded emissive layers are costly and not scalable due to the need for multiple linear sources and shadow masks, which can lead to unacceptably long response times and poor scalability to large manufacturing dimensions.
Innovation Solution
A multi-nozzle OVJP arrangement is used to deposit organic emissive layers with varying host-to-dopant ratios, allowing for sequential and adjustable deposition of mixtures over a substrate, enabling the formation of graded emissive layers with improved manufacturing efficiency and scalability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional methods using multiple linear sources and shadow masks are used to manufacture graded emissive layers, then manufacturing precision can be achieved, but device complexity and manufacturing cost increase significantly
Solution Approach 1:
The patent divides the single complex shadow mask system into multiple simpler nozzle units, each capable of depositing specific dopant concentrations. This segmentation allows the complex graded layer deposition task to be distributed across multiple simple, identical components that can be sequentially positioned and activated.
Solution Approach 2:
The patent introduces dynamic positioning of nozzles relative to the substrate, allowing the same nozzle to deposit different dopant concentrations at different positions by moving to predetermined locations. This dynamic approach replaces the static shadow mask with a movable, reconfigurable deposition system.
2Manufacturing precision
If traditional shadow mask methods are used for graded emissive layer deposition, then manufacturing precision is maintained, but productivity decreases due to long response times
Solution Approach 1:
The patent pre-calculates and stores the optimal deposition parameters (dopant concentration, nozzle position, deposition rate) for creating graded emissive layers. This preliminary preparation allows the manufacturing process to execute quickly by simply retrieving and applying pre-determined parameters rather than calculating them in real-time.
Solution Approach 2:
The patent replaces the mechanical shadow mask system with a computer-controlled nozzle positioning and deposition rate control system. This substitution enables faster response times through electronic control rather than mechanical adjustments, significantly improving productivity while maintaining precision.
3Manufacturing precision
If multiple linear sources and shadow masks are used for graded emissive layer manufacturing, then deposition precision is achieved, but scalability to large manufacturing dimensions is poor
Solution Approach 1:
The patent designs the nozzle system to be universal and multi-functional, where the same nozzle can deposit various dopant concentrations by adjusting deposition parameters. This universal nozzle design can be applied to substrates of different sizes and configurations, enabling scalability from small to large manufacturing dimensions without requiring specialized equipment for each size.
Solution Approach 2:
The patent transitions from the two-dimensional shadow mask approach to a three-dimensional nozzle positioning system that can approach the substrate from above. This dimensional change allows the deposition system to scale to larger substrate areas by moving the nozzle across the surface rather than being constrained by the fixed shadow mask geometry.
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 enables low-cost, high-throughput production of OLEDs with graded emissive layers, reducing manufacturing complexity and enhancing scalability by using OVJP nozzles to adjust the concentration of organic materials, resulting in improved OLED performance and manufacturing efficiency.
Implementation Method 1
Organic vapor jet printing (OVJP) has emerged as a promising technique for the fabrication of organic light emitting devices (OLEDs)
Implementation Method 2
A nozzle group may encompass two or more nozzles... each nozzle containing a mixture with a given host to dopant ratio that is different from the ratio in at least one other nozzle in the group of nozzles. The nozzles in the nozzle group may each deposit their respective mixture over the same area of a substrate
Data Source
AI summary
An emissive layer deposited in graded manner using a plurality of nozzles is disclosed. A mixtures ejected from the plurality of nozzles may contain varying concentrations of host-to-dopant material. The nozzles, as disclosed, may be arranged in a sequential manner such that the order of the sequence is based on varying concentration of the host-to-dopant material. The nozzles may be configured to translate relative to an area of a substrate to allow sequential deposition.