Accession Number : ADA182962
Title : A New Class of Chemical Sensors for Gases Based on Photoluminescence from Semiconductor-Derived Interfaces.
Descriptive Note : Technical rept. 25 Apr 87,
Corporate Author : WISCONSIN UNIV-MADISON DEPT OF CHEMISTRY
Personal Author(s) : Meyer,Gerald J ; Lisensky,George C ; Ellis,Arthur B
PDF Url : ADA182962
Report Date : 08 Jul 1987
Pagination or Media Count : 13
Abstract : The photoluminescence (PL) of semiconductors can be perturbed by exposure of the solid to gases. These physicochemial interactions occurring at the semiconductor surface can be exploited to create a new class of chemical sensors. For homogeneous semiconductors, a dead-layer model has been used to correlate changes in PL intensity with variations in the depletion width W caused by the gas. A graded n-CdSxSe1-x substrate permits modulation of the PL spectral distribution by gases and is color-coded to permit PL changes to be correlated with variations in the effective electric field present in the solid. Three semiconductors that have been chemically derivatized with ferrocene can sense volatile oxidants and reductants; and etched semiconductors can respond to sulfur dioxide and ammonia, presumably through acid-base interactions. All of the structures lend themselves to device fabrication by use of optical fiber technology. Keywords: Photoluminescence; Dead-layer model; Depletion width; Surface recombination velocity; Chemical sensors, Hydrogen, Ammonia, Sulfur dioxide, Iodine, Hydrazine, and Cadium compounds.
Descriptors : *GAS DETECTORS, *SEMICONDUCTORS, ACID BASE EQUILIBRIUM, INTERACTIONS, AMMONIA, LAYERS, MODELS, DEPLETION, WIDTH, ETCHING, GASES, CHEMICALS, DETECTORS, DEPLETION, ELECTRIC FIELDS, FERROCENES, INTERFACES, SURFACE CHEMISTRY, SEMICONDUCTOR DEVICES, PHYSICOCHEMICAL PROPERTIES, ETCHED CRYSTALS, CADMIUM, SELENIUM, SULFUR, PALLADIUM, ELECTRON SPECTROSCOPY, SPUTTERING, SINGLE CRYSTALS, HYDROGEN, MODULATION, PHOTOLUMINESCENCE, DIOXIDES, SULFUR OXIDES, HYDRAZINES, IODINE, SPECTRAL ENERGY DISTRIBUTION, RECOMBINATION REACTIONS, VELOCITY
Subject Categories : Solid State Physics
Electrical and Electronic Equipment
Fiber Optics and Integrated Optics
Distribution Statement : APPROVED FOR PUBLIC RELEASE