Characterization of TiO2 nanocrystalline thin film by scanning tunneling microscopy and scanning tunneling spectroscopy
| Autor: | Weibo Wang, Ruifeng Lin, Xurui Xiao, Yuan Lin |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Materials science
business.industry Band gap Scanning tunneling spectroscopy Analytical chemistry General Physics and Astronomy Surfaces and Interfaces General Chemistry Condensed Matter Physics Nanocrystalline material Surfaces Coatings and Films law.invention Semiconductor law Surface roughness Thin film Scanning tunneling microscope business Surface states |
| Zdroj: | Applied Surface Science. 143:169-173 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/s0169-4332(98)00928-3 |
| Popis: | TiO 2 nanocrystalline semiconductor films have been studied by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The presence of interconnected TiO 2 nanocrystallites with mean diameters of 30 nm and different size of pores were indicated in the STM images. Surface structural features were characterized by fractal dimension analysis in terms of surface roughness. Tunneling current vs. bias and differential conductance spectra were measured for as prepared and air-stored nanocrystalline thin films. The results obtained by statistical analysis show that surface bandgap energy of TiO 2 nanocrystallites of as prepared thin film was 3.10±0.08 eV and quite different surface bandgap energy of 1.76±0.19 eV was observed for TiO 2 nanocrystallites in air-stored thin film. Negative shifts of onset potential of differential conductance in both negative and positive bias and the presence of surface states at 1.59±0.16 V for TiO 2 nanocrystallites of air-stored thin films revealed a difference in surface electronic properties for both TiO 2 nanocrystalline thin films. |
| Databáze: | OpenAIRE |
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