Long-range Passivation of Phosphorus Impurity Atoms by Pb-centers and the Emergence of Barriers for Electrons in n-type Porous Silicon

Authors F.A. Ptashchenko

State University “Odessa Maritime Academy”, 8, Didrikhson Str., 65029 Odessa, Ukraine

Е-mail fed.ptas@gmail.com
Issue Volume 10, Year 2018, Number 5
Dates Received 11 August 2018; revised manuscript received 22 October 2018; published online 29 October 2018
Citation F.A. Ptashchenko, J. Nano- Electron. Phys. 10 No 5, 05017 (2018)
DOI https://doi.org/10.21272/jnep.10(5).05017
PACS Number(s) 68.43.Bc, 82.65._r
Keywords DFT calculations, Porous silicon (3) , Pb-centers, Coulomb blockade.

DFT calculations showed that the passivation of phosphorus impurity atoms in n-type porous silicon (n-PS) by surface silicon atoms with dangling bonds (pb-centers) can occur at large distances – up to 25 Å, that is, through dozens of atomic layers. The negative charge of the pb-centers, arising in this case, causes the appearance of regions of reduced potential and Coulomb barriers for free electrons in n-PS. This allows one to explain the low concentration of free charge carriers and the low conductivity of n-PS as compared to the original silicon substrate.

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