In thermoelectricity, silicon nanostructures represent an interesting alternative to conventional thermoelectric materials due to Si abundance, non-toxic nature and its compatibility with CMOS technology. Researchers have investigated methods to enhance the silicon figure of merit zT by increasing the σ/κ ratio; decreasing the thermal conductivity κ by (i) using nanometric structure such as thin membranes or nanowires, (ii) roughening, (iii) oxidization of the surface achieved relatively low value of κ.