Effect of Filament Bias on the Properties of Amorphous and Nanocrystalline Silicon from Hot-Wire Chemical Vapor Deposition

Abstract

At the high temperatures during hot-wire assisted chemical vapor deposition, ther- mal emission of electrons from the filament occurs. We studied the effect of filament bias, and thus the filament-to-substrate current, on the structural, electronic and optical properties of amorphous and nanocrystalline silicon deposited by this method. The current drawn by the substrate can be varied by many orders of magnitude as thermally emitted electrons are increasingly collected with applied bias voltage. The crystallinity of the nanocrystalline samples is not affected by the bias voltage. The defect density in amorphous silicon is affected by the electron bombardment at high bias voltage only, for which we also find a significant reduction in the mobility-lifetime product from steady-state photoconductivity.

Effects of proton irradiation on the photoelectronic properties of microcrystalline silicon

“…The line is a guide for the eye. The increase in ls product with shift of the Fermi level towards the conduction band, is typically found for a-Si:H [13][14][15][16] and also for lc-Si:H [17][18][19]. The irradiated samples fall well into the typical variation of ls with r d before irradiation (upper full symbols).…”

Transient Photoconductivity for the Identification of Spatial Inhomogeneities in the Defect Density in Amorphous Silicon

“…We studied hot-wire a-Si : H deposited on Corning 7059 glass in a high-vacuum deposition system at the Institut fü r Physikalische Elektronik, Universitä t Stuttgart. Some typical properties of the material from this deposition system are described elsewhere [13]. Coplanar aluminium contacts with a 0.05 cm gap and 0.5 cm wide were deposited onto the a-Si : H film.…”