OLED Layer Formation via Ring-Opening Crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic light-emitting diode (OLED) technologies face challenges in forming stable and insoluble layers using solution processing methods, which can lead to layer dissolution and performance issues due to the solubility of deposited materials.
Innovation Solution
A method involving the deposition of a precursor layer comprising a compound of formula (I) that undergoes a ring-opening addition reaction, reducing solubility and allowing for the formation of stable layers through reaction with itself or a non-polymeric co-reactant, thereby preventing layer dissolution during subsequent processing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solution processing methods are used to deposit organic layers in OLEDs, then manufacturing ease and flexibility are improved, but layer dissolution and instability occur during subsequent processing
Solution Approach 1:
The patent applies preliminary action by incorporating crosslinkable functional groups (such as epoxide, oxetane, or cyclobutane rings) into the organic layer materials before deposition. These groups remain dormant during solution processing and solution-based deposition, but are subsequently activated by thermal or UV treatment to form crosslinked networks that prevent layer dissolution. This allows the material to be processed in solution form first, then stabilized in a second step, resolving the contradiction between solution processability and layer stability.
2Reliability
If crosslinking is performed to prevent layer dissolution, then layer stability is improved, but device complexity and processing steps increase
Solution Approach 1:
The patent merges the deposition and crosslinking steps by using materials that can be deposited from solution and then crosslinked in situ. The crosslinkable functional groups are integrated into the molecular structure of the organic layer materials themselves, so that a single deposited layer performs both the function of the organic layer and the crosslinking function. This reduces the need for separate crosslinking layers or additional processing equipment, thereby reducing overall device complexity despite adding a crosslinking step.
3Reliability
If reactive groups are incorporated into organic layer materials, then layer stability through crosslinking is improved, but material solubility and processability may worsen
Solution Approach 1:
The patent applies local quality by incorporating crosslinkable functional groups as minor substituents on the organic layer material molecules rather than as the main molecular structure. For example, small percentages (5-50 mol%) of monomers containing epoxide, oxetane, or cyclobutane groups are blended with or copolymerized into the bulk organic layer material. This allows the majority of the material to maintain its inherent solubility and processability characteristics, while the localized reactive groups provide crosslinking functionality when activated, thus resolving the contradiction between crosslinking capability and solubility.
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 the formation of stable and insoluble layers in OLEDs, enhancing the manufacturing process by reducing solubility and allowing for the use of solution processing methods without layer dissolution, thus improving the overall performance and reliability of OLED devices.
Implementation Method 1
reacting the compound of formula (I) in a ring-opening addition reaction
Data Source
Figure 1
AI summary
Method and Compound A method of forming a layer of an electronic device, for example an organic light-emitting device, the method comprising the step of depositing a precursor layer comprising a compound of formula (I) and reacting the compound of formula (I) in a ring-opening addition reaction: Core-(Reactive Group)n (I) wherein Core is a non-polymeric core group; and each Reactive Group, which may be the same or different in each occurrence, is a group of formula (II): wherein Sp1 independently in each occurrence represents a spacer group; w independently in each occurrence is 0 or 1; Ar in each occurrence independently represents an aryl or heteroaryl group; R1 in each occurrence independently represents H or a substituent, with the proviso that at least one R1 is a substituent; n is at least 1; and* is a point of attachment of the group of formula (II) to the Core; and wherein the compound of formula (I) reacts with itself or with a non-polymeric co-reactant.