Organic thin-film transistors (OTFTs) have lived to see great improvements in recent years. This review presents new insight into conduction mechanisms and performance characteristics, as well as opportunities for modeling properties of OTFTs. The shifted focus in research from novel chemical structures to fabrication technologies that optimize morphology and structural order is underscored by chapters on vacuum-deposited and solution-processed organic semiconducting films. Finally, progress in the growing field of the n-type OTFTs is discussed in ample detail. The Figure, showing a pentacene film edge on SiO2, illustrates the morphology issue.

Organic Thin Film Transistors for Large Area Electronics

About Supramolecular Assemblies of π-Conjugated Systems

Graphenes as potential material for electronics.

Organic-inorganic hybrid materials promise both the superior carrier mobility of inorganic semiconductors and the processability of organic materials A thin-film field-effect transistor having an organic-inorganic hybrid material as the semiconducting channel was demonstrated Hybrids based on the perovskite structure crystallize from solution to form oriented molecular-scale composites of alternating organic and inorganic sheets Spin-coated thin films of the semiconducting perovskite (C(6)H(5)C(2)H(4)NH(3))(2)SnI(4) form the conducting channel, with field-effect mobilities of 06 square centimeters per volt-second and current modulation greater than 10(4) Molecular engineering of the organic and inorganic components of the hybrids is expected to further improve device performance for low-cost thin-film transistors

https://science.sciencemag.org/content/sci/286/5441/945.full.pdf

Organic-inorganic hybrid materials as semiconducting channels in thin-film field-effect transistors

Acenes have long been the subject of intense study because of the unique electronic properties associated with their pi-bond topology. Recent reports of impressive semiconductor properties of larger homologues have reinvigorated research in this field, leading to new methods for their synthesis, functionalization, and purification, as well as for fabricating organic electronic components. Studies performed on high-purity acene single crystals revealed their intrinsic electronic properties and provide useful benchmarks for thin film device research. New approaches to add functionality were developed to improve the processability of these materials in solution. These new functionalization strategies have recently allowed the synthesis of acenes larger than pentacene, which have hitherto been largely unavailable and poorly studied, as well as investigation of their associated structure/property relationships.

The larger acenes: versatile organic semiconductors.

A Soluble Pentacene Precursor: Synthesis, Solid‐State Conversion into Pentacene and Application in a Field‐Effect Transistor

Diode-like current-voltage curves for a single molecule-tunneling spectroscopy with submolecular resolution of an alkylated, pericondensed hexabenzocoronene

Columnar mesophases of alkylated hexa-peri-hexabenzocoronenes with remarkably large phase widths

Metal‐insulator‐semiconductor field‐effect transistors have been constructed with pentacene as the active semiconductor. The pentacene is processed by spin coating from a soluble precursor. A simple thermal conversion yields transistors with carrier mobilities as high as 9×10−3 cm2 V−1 s−1 and current modulations of the order of 105. Depletion of charge is essential to the device operation. Data for an invertor exhibiting voltage amplification are presented.

Precursor route pentacene metal-insulator-semiconductor field-effect transistors

The hexa-tert-butyl substituted hexa-peri-hexabenzocoronene was synthesized in an overall yield of 83% from 4-tert-butylphenylacetylene. The key step was the oxidative cyclodehydrogenation of hexa(4-tert-butylphenyl)benzene with anhydrous FeCl3 in CH2Cl2 The high solubility of hexa-tert-butyl-hexa-peri-hexabenzocoronene in common organic solvents allowed a comprehensive spectroscopic characterization of this compound in solution. Electrochemical oxidation at -30 degrees C in the presence of tetrabutylammonium hexafluoroarsenate led to the formation of a stable radical cation salt. Reaction of hexa-tert-butyl-hexa-peri-hexabenzocoronene with an excess of tricarbonyl(naphthalene)chromium in THF/dioxane afforded a mixture of mono- and bis-tricarbonylchromium complexes which could be separated by chromatography. The molecular structures of the parent compound, its radical cation salt and its mono- tricarbonylchromium complex were determined by X-ray analysis and discussed in detail. Remarkably, the crystal structures of these compounds are mainly dominated by the formation of dimers of the aromatic cores.

P. Herwig

Papers

A Soluble Pentacene Precursor: Synthesis, Solid‐State Conversion into Pentacene and Application in a Field‐Effect Transistor

Diode-like current-voltage curves for a single molecule-tunneling spectroscopy with submolecular resolution of an alkylated, pericondensed hexabenzocoronene

Columnar mesophases of alkylated hexa-peri-hexabenzocoronenes with remarkably large phase widths

Precursor route pentacene metal-insulator-semiconductor field-effect transistors

Synthesis and structural characterization of hexa-tert-butyl-hexa-peri-hexabenzocoronene, its radical cation salt and its tricarbonylchromium complex