Resistance to Unwanted Photo-Oxidation of Multi-Acene Molecules.

Although long acenes remain a key class of π-conjugated molecules for numerous applications, photoinduced oxidation upon exposure of the acene to light, often through sensitization of O, is an important reaction requiring mitigation for most applications. In response to this ongoing challenge, this paper presents a series of four new diarylethynyl-substituted long acenes-three tetracenes and one anthradithiophene-in which the arylene pendants are either benzene, naphthalene, or anthracene. UV/vis and fluorescence spectroscopy reveals that the anthracene-substituted derivatives fluoresce poorly (Φ < 0.

Review of Gravimetric Sensing of Volatile Organic Compounds.

Volatile organic compounds (VOCs) are pervasive in the environment. Since the early 1980s, substantial work has examined the detection of these materials, as they can indicate environmental changes that can affect human health. VOCs and similar compounds present a very specific sensing problem in that they are not reactive and often nonpolar, so it is difficult to find materials that selectively bind or adsorb them.

Molecular Rectifiers on Silicon: High Performance by Enhancing Top-Electrode/Molecule Coupling.

One of the simplest molecular-scale electronic devices is the molecular rectifier. In spite of considerable efforts aimed at understanding structure-property relationships in these systems, devices with predictable and stable electronic properties are yet to be developed. Here, we demonstrate highly efficient current rectification in a new class of compounds that form self-assembled monolayers on silicon.

A simple and robust approach to reducing contact resistance in organic transistors.

Efficient injection of charge carriers from the contacts into the semiconductor layer is crucial for achieving high-performance organic devices. The potential drop necessary to accomplish this process yields a resistance associated with the contacts, namely the contact resistance. A large contact resistance can limit the operation of devices and even lead to inaccuracies in the extraction of the device parameters.

Fluorinated benzalkylsilane molecular rectifiers.

We report on the synthesis and electrical properties of nine new alkylated silane self-assembled monolayers (SAMs) - (EtO)Si(CH)N = CHPhX where n = 3 or 11 and X = 4-CF 3,5-CF, 3-F-4-CF, 4-F, or 2,3,4,5,6-F, and explore their rectification behavior in relation to their molecular structure. The electrical properties of the films were examined in a metal/insulator/metal configuration, with a highly-doped silicon bottom contact and a eutectic gallium-indium liquid metal (EGaIn) top contact. The junctions exhibit high yields (>90%), a remarkable resistance to bias stress, and current rectification ratios (R) between 20 and 200 depending on the structure, degree of order, and internal dipole of each molecule.

Versatile organic transistors by solution processing.

A selection of the latest developments in organic electronic materials and organic field-effect transistor (OFET) devices is reviewed here with an emphasis on the synthetic and manufacturing versatility, ease of processing, and low cost offered by solution processability. At the heart of these benefits is the nature of the weak van der Waals intermolecular interactions inherent to organic compounds. This allows processability with a relatively small amount of energy investment.