Lattice thermal conductivity of nanoporous Si: Molecular dynamics study

Lattice thermal conductivity kappa(l) of Si with nanometer-sized pores along the [001] direction is calculated as a function of pore diameter (d(p)) and pore spacing (d(s)) by employing a molecular dynamics approach. Our results show that kappa(l) across pores is smaller than the bulk value by over two orders of magnitude at room temperature, and that it decreases (increases) as a function of d(p) (d(s)) for fixed d(s) (d(p)). This behavior is shown to originate from the reduction in the channels for phonon transport and the increased phonon scattering at the pore surfaces. (C) 2007 American Institute of Physics.