The density of states in silicon nanostructures determined by space-charge-limited current measurements

Abstract

Space-charge-limited current ͑SCLC͒ flow was investigated as a function of applied potential and specimen thickness in nanocrystalline silicon films prepared by electrochemical anodization. From the analysis of the current-voltage (J -V) characteristics in the SCLC regime, the density of states distribution near the Fermi level was determined. The agreement between the experimental J -V characteristics and the theoretical curve strongly implies that the current flow is entirely controlled by localized states situated at the quasi-Fermi level.

Electrical transport phenomena in nanostructured porous-silicon films

“…where N v is the effective density of energy states in the valence band, N t (s) is the density of single level traps with energy E t . This behavior is characteristic of the carrier transport where the carrier dispersion is mainly produced by ionized traps [24,25]. It must be pointed out that at high bias all the I-V curves returns to equal values described by Eq.…”

“…4 is used to consider the occupation factor θ of the dominant traps, the Eq. 4 is regularly used [24].…”

The Mechanism of Metal-Assisted Etching of Silicon

“…Most of the reports available on gold, copper, palladium, indium, and titanium as contact metals to PSi are found rectifying (Han et al 1994;Jeske et al 1995;Simons et al 1995;Diligenti et al 1996;Ichinohe et al 1996;Angelescu and Kleps 1998;Matsumoto et al 1998;Skryshevsky et al 1998;Slobodchikov et al 1998Slobodchikov et al , 1999Lue et al 1999;Bhattacharya et al 2000;Vikulov et al 2000;Ghosh et al 2002a;Rabinal and Mulimani 2007;Gallach et al 2012). The metal alloys like Au-In, In-Sn, and so on showed rectifying behavior (Angelescu and Kleps 1998).…”

“…Al p Evaporation Deresmes et al 1995;Stievenard and Deresmes 1995;Zimin et al 1995;Angelescu and Kleps 1998;Skryshevsky et al 1998;Martin-Palma et al 1999;Rabinal and Mulimani 2007;Cherif et al 2013 Sputtering Anderson et al 1991;Zimin and Bragin 1999 n Evaporation Zimin et al 1995;Diligenti et al 1996 Sputtering Anderson et al 1991;Zimin and Bragin 1999 Au p Evaporation Angelescu and Kleps 1998;Matsumoto et al 1998;Lue et al 1999;Bhattacharya et al 2000;Rabinal andMulimani 2007 Sputtering Han et al 1994;Ichinohe et al 1996;Gallach et al 2012 Electroless Jeske et al 1995 n Evaporation Simons et al 1995;Diligenti et al 1996 Ag where R s is the series resistance, and I s is the saturation current, which can be expressed as…”

“…In both the cases, after a long time of exposure to the ambient air, there is a tendency of R S and n to reach a saturation value as shown in Figure 14.2, implying a saturation of the amount of impurities absorbed by the porous structure. The huge numbers of surface states, interface states, and volume traps, of the order of 10 15 cm -3 eV -1 are present in the quasi-Fermi level of PSi layer (Matsumoto et al 1998), mainly originated from its nanostructure. These defect states are responsible for the creation of the recombination centers, the slow uncontrolled surface oxidation (Beckmann 1965;Petrova et al 2000;Astrova et al 2002;Karacali et al 2003), Fermi-level pinning Kanungo et al 2009a), and hinder the electrical response of the PSi-Si interface.…”