Disentangling surface, bulk, and space-charge-layer conductivity in Si(111)-(7 x 7).
Phys Rev Lett
; 97(20): 206803, 2006 Nov 17.
Article
de En
| MEDLINE
| ID: mdl-17155703
ABSTRACT
A novel approach for extracting genuine surface conductivities is presented and illustrated using the unresolved example of Si(111)-(7 x 7). Its temperature-dependent conductivity was measured with a microscopic four point probe between room temperature and 100 K. At room temperature the measured conductance corresponds to that expected from the bulk doping level. However, as the temperatures is lowered below approximately 200 K, the conductance decreases by several orders of magnitude in a small temperature range and it saturates at a low temperature value of approximately 4 x 10(-8) Omega(-1), irrespective of bulk doping. This abrupt transition is interpreted as the switching from bulk to surface conduction, an interpretation which is supported by a numerical model for the measured four point probe conductance. The value of the surface conductance is considerably lower than that of a good metal.
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Collection:
01-internacional
Base de données:
MEDLINE
Langue:
En
Journal:
Phys Rev Lett
Année:
2006
Type de document:
Article
Pays d'affiliation:
Danemark