Electronic Properties of Polycrystalline and Amorphous WO3 Investigated with Scanning Tunnelling Spectroscopy
The potential of Scanning Tunnelling Spectroscopy in the investigation of the local electronic properties of materials used as gas sensors is presented and discussed, focusing on the case of polycrystalline and amorphous WO3. By taking I-V curves it can be evidenced, with sub-nanometer spatial resolution, the difference in the conductivity measured at the boundaries and on the surface of individual nanoparticles. This experimental information can be used to derive an unprecedented detailed microscopic picture of the electric behaviour of such materials. Accordingly new models for the gas sensing mechanism of thin films of WO3 and other similar metal-oxide semiconductors can be proposed.
KeywordsInterstitial Region Scan Tunnelling Spectroscopy Crystallite Boundary Scan Tunnelling Spectroscopy Measure Local Electronic Property
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