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 5×10¹¹ and 1×10¹⁴K/s; the latter is the slowest quenching rate in MD simulations previously performed. Although the atomic configurations formed by the cooling rate of 10¹⁴K/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 ≈4 and tetrahedral bonds predominated. The structural and dynamical properties of a-Si generated by a cooling rate with ~10¹²K/s were in excellent agreement with those of a-Si obtained experimentally.