Electronic sensing of vapors with organic transistors

Abstract

We show that organic thin-film transistors have suitable properties for use in gas sensors. Such sensors possess sensitivity and reproducibility in recognizing a range of gaseous analytes. A wealth of opportunities for chemical recognition arise from the variety of mechanisms associated with different semiconductor–analyte interactions, the ability to vary the chemical constitution of the semiconductor end/side groups, and also the nature of the thin-film morphology.

Organic Thin-Film Transistors as Plastic Analytical Sensors

“…These polycrystalline films have been exposed to different analytes, such as alcohols, ketones, thiols, nitriles, and ester and ring compounds; on and off responses have been measured (6). Evidence supports the model of analyte molecules being adsorbed, or even trapped, at the surface of the grains-no film swelling has been detected upon exposure (39).…”

“…The transient source-drain currents in the absence (baseline current) and presence of the analyte (I analyte ) are measured with the device operating in pulsed mode (6). Pulses of saturated vapors of the analyte in N 2 and in air are delivered by solenoid valves, which control molecular delivery from an analyte reservoir driven by a peristaltic pump (Figure 3a).…”

“…Organic thin-film transistors (OTFTs) are field-effect devices with organic or polymer thin-film semiconductors as channel material. They can act as multiparametric sensors (4 ), with remarkable response repeatability, and as semi-CPbased sensing circuits (5,6 ) . Color-coded plots of OTFTs responses after 13 h of exposure to alcohols are shown on the previous page.…”

Electronic transport properties of pentacene single crystals upon exposure to air

“…This can be attributed in part to the fact that the performance of the devices depends critically on the environmental conditions. [9][10][11] We report the electronic properties of pentacene single crystals under controlled conditions of pressure, gas composition, illumination, and in time. We provide experimental evidence that the influence of air on the charge carrier conduction consists of two separate, distinguishable contributions.…”

The nature and role of trap states in a dendrimer-based organic field-effect transistor explosive sensor

“…16,17 The majority of OFETs reported to date, particularly in sensor applications, have polymeric or small molecule organic semiconductor channels. 11,[13][14][15][16][17][18][19][20] We have recently demonstrated sensing OFETs based upon a third class of materials-namely semiconducting dendrimers. 21 Dendrimers are branched macromolecules composed of a core, branching units and surface groups.…”