Molecular dynamics investigations of boron doping in a-Si:H

摘要

The rather low doping efficiency of B in a-Si:H is almost always expalined by the argument that almost all of the B is incorporated into three-fold coordinated sites and that B is inert or non-doping in this configuration.Using ab initio modlecular dynamics,we have studied the energetics and doping (electronic structure) consequences of B incorporation into a-Si:H both with and without H passivation.Our results suggest that the conventional view is in error and that the low doping efficiency is primarily due to H passivation.These results are consistent with the low doping efficiency of B as well as NMR studies on the large electric field gradients experienced by the B atoms and on NMR double resonance studies of B-H neighboring distances.