Evaluation of GaN and In0.2Ga0.8N Semiconductors as Potentiometric Anion Selective Electrodes |
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| Authors: | Rozalina Dimitrova Lionel Catalan Dimiter Alexandrov Aicheng Chen |
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| Institution: | 1. Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B?5E1, Canada;2. Department of Electrical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B?5E1, Canada;3. Department of Chemistry, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B?5E1, Canada |
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| Abstract: | The response of potentiometric anion selective electrodes consisting of undoped GaN or In0.2Ga0.8N films grown on Al2O3 (sapphire) was measured in electrolyte solutions of F?, NO3?, Cl?, SCN?, ClO4? or Br? anions at concentrations ranging from 10?6 to 10?1 M. The slope of the linear regions varied between ?32.8 and ?51.9 mV/decade for the GaN electrode and between ?31.0 and ?72.0 mV/decade for the In0.2Ga0.8N electrode. The drift of the GaN electrode reached 1.57 mV/day in KNO3 solutions, whereas the drift of the In0.2Ga0.8N electrode could not be evaluated due to large drops in the slope of its linear range over time. Both electrodes were sensitive to pH variations over the pH range from 12.8 to 1.3. The GaN electrode surface could be electrochemically etched under anodic polarization; however, both GaN and In0.2Ga0.8N electrodes remained chemically stable and mechanically intact under open circuit conditions even after prolonged use. |
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| Keywords: | Anion selective electrodes pH sensitivity GaN In0 2Ga0 8N Etching |
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