STRUCTURE OF A-SI-H FROM HARRIS-FUNCTIONAL MOLECULAR-DYNAMICS

Using Harris-functional molecular dynamics, we generate a 242-atom mod el of hydrogenated amorphous silicon. Our model has a hydrogen concent ration of 11%, which is in the range of device-quality films. To produ ce our model, we first form a liquid at similar to 1800 K and then que nch to produce an amorphous structure at similar to 300 K. We find our model produces radial distribution functions, which compare favorably with previous experimental and theoretical results. We investigate th e limitations of molecular-dynamics-based methods for producing amorph ous structures. In addition we examine the hydrogen structures present , which include isolated SiH bonds and clusters of 2-7 Si-H bonds. The role of hydrogen and the relevance of these clusters is discussed.