Investigation of the sensitivity, selectivity, and reversibility of the chemically-sensitive field-effect transistor (CHEMFET) to detect nitrogen dioxide, dimethyl methylphosphonate, and boron trifluoride. Master's thesis

Technical Report · Wed Sep 01 04:00:00 EDT 1993

OSTI ID:5721163

Hauschild, N T

This study investigated the sensitivity, selectivity, and reversibility of a chemically-sensitive field-effect transistor (CHEMFET) gas microsensor. Various physical operating parameters were tested to determine which produced the most significant sensitivity, selectivity, and reversibility which were computed from response changes generated from electrical conductivity modulations when exposed to challenge gases. The variable operating parameters included: thinfilm material, film thickness, challenge gas specie, challenge gas concentration, and operating temperature. Copper phthalocyanine and lead phthalocyanine were used as thin films to detect the following challenge gases: nitrogen dioxide, dimethyl methylphosphonate, boron trifluoride, methanol, carbon monoxide, vinyl chloride, and trichloroethylene. Tests revealed that copper phthalocyanine was the most sensitive to dimethyl methylphosphonate and boron trifluoride, whereas lead phthalocyanine was the most sensitive to the remaining challenge gases. The CHEMFET was selective to the binary challenge gas combinations. The films were most selective for nitrogen dioxide. The CHEMFET was fully reversibly, and the time duration for full reversibility increased with increasing challenge gas concentrations and increasing time of exposure.

• Research Organization: Air Force Inst. of Tech., Wright-Patterson AFB, OH (United States). School of Engineering
• OSTI ID: 5721163
• Report Number(s): AD-A-270625/7/XAB; AFIT/GE/ENG--93S-10
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
ALCOHOLS
AROMATICS
BORON COMPOUNDS
BORON FLUORIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHLORINATED ALIPHATIC HYDROCARBONS
CHLORINATED AROMATIC HYDROCARBONS
DYES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FIELD EFFECT TRANSISTORS
FILMS
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GASES
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HALOGENATED AROMATIC HYDROCARBONS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
METHANOL
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHTHALOCYANINES
PHYSICAL PROPERTIES
SEMICONDUCTOR DEVICES
SENSITIVITY
THIN FILMS
TRANSISTORS
VINYL CHLORIDE