Generation of amorphous silicon structures by rapid quenching: A molecular-dynamics study

Amorphous silicon (a-Si) networks have been generated from melted Si with various quenching rates by molecular-dynamics (MD) simulations employing the Tersoff potential. The cooling rates were set between 5 x 10(11) and 1 x 10(14) K/s; the latter is the slowest quenching rate in MD simulations previously performed. Although the atomic configurations formed by the cooling rate of 10(14) K/s could reproduce the radial distribution function of a-Si obtained experimentally, they contained numerous structural defects such as threefold- and fivefold-coordinated atoms. As the cooling rate decreased, the average coordination number became approximate to 4 and tetrahedral bonds predominated. The structural and dynamical properties of a-Si generated by a cooling rate with similar to 10(12) K/s were in excellent agreement with those of a-Si obtained experimentally.