Piezoresistivity of silicon quantum well wire

In this paper, the piezoresistive coefficient of silicon quantum well wire has been estimated using k.p theory and the deformation potential concept and has been observed to be 5.5 times higher compared to that of the bulk for a quantum well width of 2.5 nm. The effect of the quantum confinement of holes on the bandstructure of nanocrystalline silicon resulting in the separation of light hole and heavy hole subbands has been considered. On the application of stress, there is a further shift in the energy levels of heavy hole and light hole bands, leading to a change in the carrier concentration and effective mass of holes in the respective subbands which ultimately is responsible for the enhancement of the piezoresistive coefficient. The change in the energy levels and effective mass are significant below well width dimensions of 5 and 20 nm, respectively.