“…However, the ohmic and rectifying nature depend on some properties of PSi like type of conductivity, porosity, and resistivity. For example, it was found that while PSi with low porosity and low resistivity forms ohmic contact with Al, both n-and p-type PSi with high resistivity forms Al-PSi contact of rectifying behavior (Simons et al 1995;Zimin et al 1995Zimin et al , 1998Kanungo et al 2009a). There are reports on the ohmic behavior of Al to PSi after the surface modification, presumably due to the reduction of the porosity through surface passivation (Kanungo et al 2009a;Maji et al 2010).…”