Electronic Detection of Low Concentrations of Organophosphorus Compounds with a Solid State Device Utilizing Supported Copper + Cuprous Oxide Island Films

摘要

This research is concerned with investigating the electronic properties modified by the exposure of a supported island film of copper + cuprous oxide to low concentrations (1-650 ppm) of diisoprophyl methylphosphonate (DIMP), and the merit of integrating these films with the distributed RC notch network detection device. Electron microscopy and associated diffraction measurements confirmed the film's structure and composition; Auger spectroscopy verified the adsorption of DIMP. DIMP exposure sensitivity is maximized for films with thicknesses less that 80 A operated at 90 C which have an applied bias greater than 10 volts (direct current). The adsorption of DIMP is quasi-reversible; that is, after a conditioning exposure and purge, the effect of successive challenges and expiations was monitored via corresponding changes in the film's conductivity. Exposure experiments for changes in resistance versus time were fitted to a two-dimensional nucleation and growth model.