UV-Patternable Polymer Blends for Photoresist-Free OTFT Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional photolithography techniques for patterning organic semiconductor layers in organic thin-film transistors (OTFTs) involve harsh oxygen plasma and aggressive solvents, which damage the OSC layer and deteriorate device performance, making them impractical for OTFT manufacturing.
Innovation Solution
Development of UV patternable organic semiconductor/isolating polymer blends comprising a diketopyrrolopyrrole-fused thiophene polymeric material blended with a non-conjugated isolating polymer, photoinitiators, and crosslinkers, allowing for UV patterning without photoresists, using thiol-ene polymerizations and radical initiators to form high-resolution patterns in air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional photolithography techniques are used for patterning organic semiconductor layers, then pattern transfer can be achieved, but harsh oxygen plasma and aggressive solvents damage the OSC layer and deteriorate device performance
Solution Approach 1:
The patent extracts and removes the harmful elements (oxygen plasma and aggressive solvents) from the patterning process by replacing them with a photoresist-free UV patterning method using organic semiconductor/isolating polymer blends, thereby eliminating damage to the OSC layer while maintaining patterning precision
Solution Approach 2:
The patent changes the chemical and physical parameters of the patterning process by using UV irradiation to induce crosslinking in the isolating polymer phase at room temperature or mild heating conditions, replacing the harsh plasma and solvent-based processes with a milder photopolymerization approach that preserves OSC layer integrity
2Manufacturing precision
If photolithography with photoresist is used, then pattern transfer is achieved, but complex photolithographic patterning methods and harsh chemicals are required
Solution Approach 1:
The patent merges the semiconductor layer and isolating polymer into a single blended layer that serves both as the functional semiconductor component and as the patterning medium, eliminating the need for separate photoresist application and processing steps
Solution Approach 2:
The isolating polymer phase within the blend performs the patterning function itself through UV-induced crosslinking, making the system self-sufficient and eliminating the need for external photoresist materials and complex photolithography procedures
3Loss of substance
If UV patterning without photoresist is implemented, then material costs and environmental impact are reduced, but the OSC layer stability must be maintained
Solution Approach 1:
The patent creates a composite material system where the organic semiconductor polymer is blended with an isolating polymer containing crosslinkable functional groups, forming a heterogeneous structure where the isolating polymer provides UV-responsive crosslinking capability while the semiconductor phase maintains its functional integrity and stability
Solution Approach 2:
The patent applies local quality by restricting UV-induced crosslinking to only the isolating polymer phase while leaving the organic semiconductor phase unchanged, thereby achieving patterning in the isolating polymer regions without affecting the stability and functionality of the OSC 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 enables efficient, high-resolution patterning of OTFTs in air, reducing material costs and environmental impact, while maintaining device performance by avoiding harsh chemicals and improving the stability of the OSC layer.
Implementation Method 1
at least one photoinitiator configured to generate active radicals
Implementation Method 2
using thiol-ene polymerizations and radical initiators to form high-resolution patterns
Data Source
AI summary
A polymer blend includes an organic semiconductor polymer blended with an isolating polymer; at least one photoinitiator for generating active radicals; and at least one crosslinker comprising C═C bonds, thiols, or combinations thereof, such that the organic semiconductor polymer is a diketopyrrolopyrrole-fused thiophene polymeric material, the fused thiophene is beta-substituted, and the isolating polymer has a non-conjugated backbone. A method of forming an organic semiconductor device having the polymer blend is also presented.