Research Information System
Thesis Type: Doctorate
Institution Of The Thesis: Gazi University, Turkey
Approval Date: 2017
Thesis Language: Turkish
Student: Irmak Karaduman
Supervisor: SELİM ACAR
Open Archive Collection: AVESIS Open Access Collection
Abstract:In this thesis, Zn1-xSnxO (x = 0.25 steps) metal oxide structures used as sensors for the electronic nasal systems used in the diagnosis of asthmatic disease were grown by the Successive Ionic Layer Adsorption and Reaction (SILAR) method; and structural and electrical characterization of metal oxide structures were performed. The samples grown by different addition ratios and number of cycles (20, 30 and 40) were examined by X-ray diffraction (XRD), Optical Absorption, Scanning Electron Microscope (SEM). Gas detection measurements were made at 30-135C temperature range to determine the working temperature of the produced structures as gas sensors. NO gas detection was examined depending on the rate of addition and the number of cycles. It was observed that the maximum sensitivity for 50 ppb NO gas was obtained in the sensors produced in 40 cycles. Sensors produced for 40 cycles annealed in a nitrogen gas environment at 300 ˚C. Thus, the effects of annealing on NO gas sensing properties were investigated. The maximum sensitivity for 20 ppb NO gas at the end of the optimization was obtained at ZnO,75Sn0,25O. Principal Componant Analysis analyzed all the data obtained statistically. While the Zn0,75Sn0,25O sample showed high sensitivity to NO gas, acceptable sensitivities were also observed for CO and NH3 gases. In order to increase selectivity, the Zn0,75Sn0,25O sample was coated with a nano porous zeolite A filter. Sensitivity to CO and NH3 gases was not observed at ambient temperature when 31% sensitivity was obtained for 20 ppb NO gas. It has been determined that Zn0,75Sn0,25O sensor, which acquires high selectivity by coating with zeolite filter, can be used as sensor surface in determination of asthma disease.