Percolation process in high-conductivity phosphorus-doped amorphous SI:H:F alloys
Journal
Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers, Series A/Chung-kuo Kung Ch'eng Hsuch K'an
Journal Volume
6
Journal Issue
4
Pages
245-249
Date Issued
1983
Author(s)
Abstract
Abstract The dark conductivity of phosphorus‐doped amorphous‐silicon alloys (a‐Si:H:F) prepared by the RF plasma decomposition of a gaseous mixture of SiF4, H2 and diluted PH3 is extremely high; it exceeds 10 (O‐cm)‐1 with only a small amount of PH3 (∼500 ppm) added in the gas phase. These doping characteristics represent a significant improvement over the doping characteristics of a‐Si:H alloys prepared by a glow‐discharge of SiH4. The improvement was found to be due to the fact that P‐doped a‐Si:H:F contains microcrystallites which are embedded in an amorphous network. The percolation process in these two‐phase systems gives rise to high conductivity. We have used transmission electron microscopy (TEM) and diffraction (TED) to determine the critical surface fraction, ρc, of crystallinity at the onset of extended conduction. The measured ρc is approximately 0.46. This percolation limit provides a basis for the analysis of the electrical properties of P‐doped a‐Si:H:F.
SDGs
Type
journal article