Mechanical and electrical properties of epitaxial Si nanowires grown by pulsed laser deposition

Abstract

We report on the elastic and piezoresistive properties of individual epitaxial Si-NWs grown on n-doped Si(111) by pulsed laser deposition. Using scanning probe microscopy, we obtained a Young’s modulus between 82 and 900 GPa for the nanowires, unaffected by the nanowire shape. A relative resistivity change is observed in the prestrained (curved) Si-NWs, which we attribute to a large piezoresistance coefficient in the NW along its axis. Assuming that for the bent NWs the effect of longitudinal stress on resistivity is compensated, the piezoresistance coefficient originating in the shear strain alone, we found a piezoresistance gauge factor (GF) of 600, which is close to the values reported in literature for Si-NWs.