In this paper we report on the frequency dependence of the AC conductivity of porous silicon in the range 10 Hz-100 kHz. Two types of testing devices have been fabricated on three different series of samples formed electrochemically using as a starting material p-type, n--type and n+-type silicon substrates. For frequencies less than 20-40 kHz the conductivity is found to follow a sublinear frequency dependence. This behaviour is typical of a carrier transport mechanism determined by an anomalous diffusion process. At higher frequencies we find that surface states influence the transport mechanism. This suggests a double-channel transport mechanism: one related to porous-silicon «volume» properties and the other more connected to the «surface» itself.
|Pages (from-to)||1187 - 1196|
|Number of pages||10|
|Journal||Nuovo Cimento della Societa Italiana di Fisica D - Condensed Matter, Atomic, Molecular and Chemical Physics, Biophysics|
|Publication status||Published - 1996|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
Di Francia, G., La Ferrara, V., Maddalena, P., Ninno, D., Odierna, L. P., & Cataudella, V. (1996). AC conductivity of porous silicon: A fractal and surface transport mechanism? Nuovo Cimento della Societa Italiana di Fisica D - Condensed Matter, Atomic, Molecular and Chemical Physics, Biophysics, 18(10), 1187 - 1196. https://doi.org/10.1007/BF02464696