Enhanced vapour sensing using silicon nanowire devices coated with Pt nanoparticle functionalized porous organic frameworks.

Recently various porous organic frameworks (POFs, crystalline or amorphous materials) have been discovered, and used for a wide range of applications, including molecular separations and catalysis. Silicon nanowires (SiNWs) have been extensively studied for diverse applications, including as transistors, solar cells, lithium ion batteries and sensors. Here we demonstrate the functionalization of SiNW surfaces with POFs and explore its effect on the electrical sensing properties of SiNW-based devices.

Metal-Organic Polyhedra-Coated Si Nanowires for the Sensitive Detection of Trace Explosives.

Surface-modified silicon nanowire-based field-effect transistors (SiNW-FETs) have proven to be a promising platform for molecular recognition in miniature sensors. In this work, we present a novel nanoFET device for the sensitive and selective detection of explosives based on affinity layers of metal-organic polyhedra (MOPs). The judicious selection of the geometric and electronic characteristics of the assembly units (organic ligands and unsaturated metal site) embedded within the MOP cage allowed for the formation of multiple charge-transfer (CT) interactions to facilitate the selective explosive inclusion.

Up-scaling graphene electronics by reproducible metal-graphene contacts.

Chemical vapor deposition (CVD) of graphene on top of metallic foils is a technologically viable method of graphene production. Fabrication of microelectronic devices with CVD grown graphene is commonly done by using photolithography and deposition of metal contacts on top of the transferred graphene layer. This processing is potentially invasive for graphene, yields large spread in device parameters, and can inhibit up-scaling.

Ionophore-containing siloprene membranes: direct comparison between conventional ion-selective electrodes and silicon nanowire-based field-effect transistors.

Siloprene-based, ion-selective membranes (ISMs) were drop-casted onto a field-effect transistor device that consisted of a single-chip array of top-down prepared silicon nanowires (SiNWs). Within one array, two sets of SiNWs were covered with ISMs, each containing two different ionophores, allowing the simultaneous sensing of K and Na ions using a flow cell. It is shown that both ions can be effectively detected in the same solution over a wide concentration range from 10(-4) to 10(-1) M without interference.

Influence of conductivity and dielectric constant of water-dioxane mixtures on the electrical response of SiNW-based FETs.

In this study, we report on the electrical response of top-down, p-type silicon nanowire field-effect transistors exposed to water and mixtures of water and dioxane. First, the capacitive coupling of the back gate and the liquid gate via an Ag/AgCl electrode were compared in water. It was found that for liquid gating smaller potentials are needed to obtain similar responses of the nanowire compared to back gating.

Robust fabrication method for silicon nanowire field effect transistors for sensing applications.

This paper demonstrates a new method for the top-down production of silicon nanowire field effect transistors for sensing applications. A simple and robust method for the fabrication of these devices is described, using only conventional CMOS (Complementary Metal Oxide Semiconductor) processing techniques making it manufacturable on large scale in a broad range of production facilities. Moreover, the process is flexible in terms of the choice of the type of front oxide of the transistor, as it is applied in a separate, independent step from the application of the surrounding oxide.