Semiconductor chemical sensor

摘要

A chemical sensor for detecting a chemical species in a gas comprises a detector element including a porous organic semiconductor comprised of a material on which the chemical species in the gas is adsorbed. The chemical sensor further comprises a power source for producing a bias voltage and a depletion region in the detector element. The chemical species percolates through the organic semiconductor and into the depletion region under the bias voltage, causing a change in the capacitance of the detector element. A light source irradiates the gas with light before entering the detector element. The light changes the chemical properties of the chemical species and enhances the adsorption selectivity of the organic semiconductor. The chemical sensor can determine both the presence and concentration of the chemical species in the gas based on the change in capacitance in the detector element. The chemical sensor can be provided in a portable unit suitable for field testing applications.