Naphthalene Diimide N-Type Semiconductors for Flexible TFTs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current organic semiconductor materials for n-channel thin film transistors exhibit limited mobility and on/off ratios, making them unsuitable for high-performance electronic devices, and require high processing temperatures, restricting the use of flexible substrates.
Innovation Solution
N,N′-dicycloalkyl-substituted naphthalene-1,4,5,8-bis(dicarboximide) compounds with aliphatic carbocyclic rings attached to imide nitrogens, allowing for high field-effect electron mobility up to 4.0 cm2/Vs and on/off ratios of at least 105, achieved through sublimation or solution-phase deposition at low substrate temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If amorphous silicon is used as semiconductor material, then manufacturing cost is reduced, but electron mobility is limited to 0.5-1.0 cm2/V sec
Solution Approach 1:
The patent changes the material parameter from inorganic amorphous silicon to organic semiconductor compounds (naphthalene-based tetracarboxylic diimides with cycloalkyl substituents), fundamentally altering the electronic structure and charge transport mechanism to achieve higher mobility while maintaining low-cost fabrication compatibility
Solution Approach 2:
The invention uses composite molecular structures combining naphthalene core with cycloalkyl substituents (cyclohexyl, cyclopentyl, cyclobutyl groups) to create organic semiconductor materials that exhibit both high electron mobility and suitability for low-temperature processing
2Reliability
If high processing temperatures (about 360° C.) are used to achieve sufficient electrical characteristics, then device performance is improved, but substrate material selection is restricted
Solution Approach 1:
The patent changes the processing temperature parameter from high (360°C for amorphous silicon) to low (below 150°C for organic semiconductors), enabling the use of flexible plastic substrates and other temperature-sensitive materials while maintaining adequate electrical performance through molecular structure optimization
3Temperature
If conventional organic semiconductor materials are used, then processing temperature is reduced, but electron mobility and on/off ratios are insufficient for high-performance devices
Solution Approach 1:
The patent applies local quality modification by introducing specific cycloalkyl substituent groups (cyclohexyl, cyclopentyl, cyclobutyl) at precise positions on the naphthalene core structure, optimizing local molecular packing and electronic properties to achieve high electron mobility while maintaining low processing temperatures
Solution Approach 2:
The invention optimizes molecular structure parameters including substituent type, position, and steric configuration to tune the HOMO-LUMO energy levels and charge transport properties, achieving electron mobility exceeding 0.1 cm2/V sec while maintaining compatibility with low-temperature processing
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 compounds provide high-performance n-channel semiconductor films that are stable in air and do not require special chemical underlayers, enabling the production of flexible electronic devices with improved mobility and on/off ratios, suitable for a wide range of electronic applications.
Implementation Method 1
achieved through sublimation or solution-phase deposition at low substrate temperatures
Data Source
AI summary
A thin film transistor comprises a layer of organic semiconductor material comprising a tetracarboxylic diimide naphthalene-based compound having, attached to each of the imide nitrogen atoms, a substituted or unsubstituted alicyclic ring system, optionally substituted with electron donating groups. Such transistors can further comprise spaced apart first and second contact means or electrodes in contact with said material. Further disclosed is a process for fabricating an organic thin-film transistor device, preferably by sublimation deposition onto a substrate, wherein the substrate temperature is no more than 100° C.