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Scanning tunneling spectroscopy of porous silicon in presence of methanol

Rahimi, F ; Sharif University of Technology | 2006

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  1. Type of Document: Article
  2. DOI: 10.1016/j.snb.2006.02.016
  3. Publisher: 2006
  4. Abstract:
  5. In this research, we used the scanning tunneling spectroscopy (STS) technique to probe the local electrical properties of the surface of meso-porous silicon and its substrate, including local density of states (DOS) in air and in methanol environment to increase our knowledge of sensing phenomena. Meso-porous silicon was prepared on p+-type Si which has high sensitivity toward methanol. Observations revealed that while the surface electrical properties of p+-type Si have not sensible change toward methanol, average local density of state of the porous layer increases after the exposure to methanol especially in the E < EF region. Moreover, large number of surface states is produced in band gap which implies that the number of free-carriers in porous silicon increases in methanol environment. This phenomenon explains the change in electrical resistivity of meso-porous Si in the presence of methanol which is the base of organic gas sensitivity of this structure. © 2006
  6. Keywords:
  7. Electric resistance ; Methanol ; Scanning tunneling microscopy ; Spectroscopic analysis ; Density of states (DOS) ; Gas sensitivity ; Scanning tunneling spectroscopy (STS) ; Porous silicon
  8. Source: Sensors and Actuators, B: Chemical ; Volume 120, Issue 1 , 2006 , Pages 172-176 ; 09254005 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0925400506000852