Highly Sensitive Air-Stable Easily Processable Gas Sensors Based on Langmuir-Schaefer Monolayer Organic Field-Effect Transistors for Multiparametric HS and NH Real-Time Detection.

A combination of low limit of detection, low power consumption, and portability makes organic field-effect transistor (OFET) chemical sensors promising for various applications in the areas of industrial safety control, food spoilage detection, and medical diagnostics. However, the OFET sensors typically lack air stability and restoration capability at room temperature. Here, we report on a new design of highly sensitive gas sensors based on Langmuir-Schaefer monolayer organic field-effect transistors (LS OFETs) prepared from organosilicon derivative of [1]benzothieno[3,2- b][1]-benzothiophene.

Luminescent Organic Semiconducting Langmuir Monolayers.

In recent years, monolayer organic field-effect devices such as transistors and sensors have demonstrated their high potential. In contrast, monolayer electroluminescent organic field-effect devices are still in their infancy. One of the key challenges here is to create an organic material that self-organizes in a monolayer and combines efficient charge transport with luminescence.

Polymer Surface Engineering for Efficient Printing of Highly Conductive Metal Nanoparticle Inks.

An approach to polymer surface modification using self-assembled layers (SALs) of functional alkoxysilanes has been developed in order to improve the printability of silver nanoparticle inks and enhance adhesion between the metal conducting layer and the flexible polymer substrate. The SALs have been fully characterized by AFM, XPS, and WCA, and the resulting printability, adhesion, and electrical conductivity of the screen-printed metal contacts have been estimated by cross-cut tape test and 4-point probe measurements. It was shown that (3-mercaptopropyl)trimethoxysilane SALs enable significant adhesion improvements for both aqueous- and organic-based silver inks, approaching nearly 100% for PEN and PDMS substrates while exhibiting relatively low sheet resistance up to 0.

Easily processable highly ordered Langmuir-Blodgett films of quaterthiophene disiloxane dimer for monolayer organic field-effect transistors.

Self-assembly of highly soluble water-stable tetramethyldisiloxane-based dimer of α,α'-dialkylquaterthiophene on the water-air interface was investigated by Langmuir, grazing incidence X-ray diffraction, and X-ray reflectivity techniques. The conditions for formation of very homogeneous crystalline monolayer Langmuir-Blodgett (LB) films of the oligomer were found. Monolayer organic field-effect transistors (OFETs) based on these LB films as a semiconducting layer showed hole mobilities up to 3 × 10(-3) cm(2)/(V s), on-off ratio of 10(5), small hysteresis, and high long-term stability.