Fabrication of Pd/PdO thin film as sensing membrane for Extended Gate Field Effect Transistor (EGFET)
碩士 === 長庚大學 === 光電工程研究所 === 102 === A palladium oxide (PdO) thin film pH sensor based on extended gate filed effect transistor (EGFET) technique is fabricated and its pH sensing properties, stability and reliability were studied. The thesis outlines the procedures of converting palladium thin films...
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2014
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| Online Access: | http://ndltd.ncl.edu.tw/handle/24115547390874272971 |
| Summary: | 碩士 === 長庚大學 === 光電工程研究所 === 102 === A palladium oxide (PdO) thin film pH sensor based on extended gate
filed effect transistor (EGFET) technique is fabricated and its pH sensing
properties, stability and reliability were studied. The thesis outlines the
procedures of converting palladium thin films into palladium oxide sensing
membrane. Pd thin film was first deposited by electron beam evaporation
technique on a sapphire substrate, followed thermal oxidation in furnace
with oxygen ambient. Comparisons were made among sensors with regards
to the effects of oxidation: reactive evaporation with oxidation, furnace
oxidation and two-step oxidation. First series of analysis has proven that
oxidation greatly enhances palladium’s sensitivity. Through further
temperature optimization, the averaged sensitivity of PdO sensor for pH
detection is approximately 62.87 mV/pH in concentrations among pH 2 to
pH 12. The hysteresis effect in 7→4→7→10→7 pH loop is about 7.9 mV.
The effect of long-term drift for PdO EGFET is 2.32 mV/hr in pH7 buffer
solution.
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