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 me find that sm face 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.
AC conductivity of porous silicon: A fractal and surface transport mechanism? / Di Francia, G.; La Ferrara, V.; Maddalena, Pasqualino; Ninno, Domenico; Odierna, L. P.; Cataudella, Vittorio. - In: NUOVO CIMENTO DELLA SOCIETÀ ITALIANA DI FISICA. D CONDENSED MATTER, ATOMIC, MOLECULAR AND CHEMICAL PHYSICS, BIOPHYSICS. - ISSN 0392-6737. - STAMPA. - 18:(1996), pp. 1187-1196. [10.1007/BF02464696]
AC conductivity of porous silicon: A fractal and surface transport mechanism?
MADDALENA, PASQUALINO;NINNO, DOMENICO;CATAUDELLA, VITTORIO
1996
Abstract
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 me find that sm face 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
