Field-effect transistor; mono- and diimide perylene and naphthalene compounds, core-substituted with one or more electron-withdrawing groups, generating the radical anions electrochemically
Inventors
Marks, Tobin J. • Wasielewski, Michael R. • Facchetti, Antonio • Ahrens, Michael J. • Jones, Brooks A. • Yoon, Myung-Han
Assignees
Northwestern University • Defense Advanced Research Projects Agency DARPA
Publication Number
US-7671202-B2
Publication Date
2010-03-02
Expiration Date
2025-01-26
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Abstract
Mono- and diimide perylene and naphthalene compounds, N- and core-substituted with electron-withdrawing groups, for use in the fabrication of various device structures.
Core Innovation
The invention relates to mono- and diimide perylene and naphthalene compounds that are core- and N-substituted with one or more electron-withdrawing groups, designed for use in fabricating various device structures including organic field-effect transistors (OFETs). These compounds generate radical anions electrochemically, enhancing their application as n-type semiconductors in devices. The compounds are functionalized to improve solubility, radical anion stability, and maintain strong π-π interactions, thereby enhancing device performance.
The problem addressed by this invention arises from the limitations of existing n-type organic semiconductors, particularly arene core diimides such as naphthalene and perylene tetracarboxylic diimides. While these materials have been investigated, they generally exhibit instability in air and unsatisfactory solubility, which hamper efficient device fabrication. Thus, there is a need for n-type semiconductor materials with improved air stability, solubility, and electronic properties suitable for high-performance OFETs and related devices.
To overcome these shortcomings, the invention provides polycyclic aromatic mono- and diimide compounds core-substituted with electron-withdrawing moieties that enhance oxidative stability and lower reduction potentials compared to unsubstituted counterparts. The compounds feature electron-withdrawing substituents such as cyano and fluorinated groups, which facilitate electron injection and stabilize radical anions. The invention also discloses methods of synthesizing such compounds and incorporating them into device structures. The compounds exhibit high solubility, large chemical and thermal stability, and strong π-π intermolecular interactions, resulting in improved field-effect mobilities and on/off current ratios when used in OFETs.
Claims Coverage
The patent includes a series of independent claims focusing on n-type semiconductor compounds, their structural formulas, substitution patterns, and their incorporation in device composites. There are three main independent claims covering compound formulas and composites.
N-type semiconductor compound with defined substitution
An n-type semiconductor compound having formula I, in which substituents R1-R12 are selected from hydrogen, electron-withdrawing groups, and moieties comprising such groups. The compound includes core and N-substitutions, with at least one of these positions occupied by an electron-withdrawing substituent to enhance electronic properties.
N-type semiconductor compound with dicyano substitution
An n-type semiconductor compound having formula III characterized by dicyano substitution at specific ring positions, with variations in alkyl or cycloalkyl moieties at other positions, providing enhanced reduction potentials and stability.
Composite comprising a substrate and semiconductor component
A composite structure comprising a substrate and a semiconductor component, wherein the semiconductor component includes compounds of formula I′ or III′ with specific substitution patterns. The semiconductor component is configured to be incorporated into device structures such as OFETs, using compounds with alkyl, substituted alkyl, cycloalkyl, or substituted aryl groups.
The independent claims collectively cover the chemical structure of novel n-type semiconductor compounds substituted with electron-withdrawing groups at specific positions, compounds with dicyano substituents, and their incorporation into composites and devices, emphasizing improved electronic characteristics and device performance.
Stated Advantages
Enhanced oxidative stability of the n-type semiconductor compounds compared to unsubstituted polycyclic compounds.
Lower reduction potentials facilitating easier electron injection and formation of radical anions.
Improved solubility of compounds enabling efficient solution processing and device fabrication.
Strong π-π intermolecular interactions promoting effective charge transport and high field-effect mobilities in OFETs.
Air stability of device operation, enabling prolonged use under ambient conditions without significant degradation.
High on/off current ratios (up to 10^5) and mobility values reaching 0.64 cm2/Vs, representing improved device performance over prior materials.
Documented Applications
Use of the disclosed mono- and diimide perylene and naphthalene compounds in organic field-effect transistors (OFETs) as n-type semiconductors.
Incorporation of the compounds into a range of device structures including organic light-emitting diodes and photovoltaic devices.
Fabrication of thin-film transistors with enhanced charge mobility and air stability by vapor deposition or solution casting of the semiconductor compounds.
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