title: Thermally Induced Nano-Structural and Optical Changes of nc-Si:H Deposited by Hot-Wire CVD.
abstract: We report on the thermally induced changes of the nano-structural and optical properties of hydrogenated nanocrystalline silicon in the temperature range 200-700 degrees C. The as-deposited sample has a high crystalline volume fraction of 53% with an average crystallite size of ~3.9 nm, where 66% of the total hydrogen is bonded as identical withSi-H monohydrides on the nano-crystallite surface. A growth in the native crystallite size and crystalline volume fraction occurs at annealing temperatures >/=400 degrees C, where hydrogen is initially removed from the crystallite grain boundaries followed by its removal from the amorphous network. The nucleation of smaller nano-crystallites at higher temperatures accounts for the enhanced porous structure and the increase in the optical band gap and average gap.
authors.forename: C J
authors.initials: CJ
authors.lastname: Arendse
authors.forename: G F
authors.initials: GF
authors.lastname: Malgas
authors.forename: T F G
authors.initials: TF
authors.lastname: Muller
authors.forename: D
authors.initials: D
authors.lastname: Knoesen
authors.forename: C J
authors.initials: CJ
authors.lastname: Oliphant
authors.forename: D E
authors.initials: DE
authors.lastname: Motaung
authors.forename: S
authors.initials: S
authors.lastname: Halindintwali
authors.forename: B W
authors.initials: BW
authors.lastname: Mwakikunga