Nanostructure of a-Si:H and Related Alloys by Small-Angle Scattering of Neutrons and X-Rays: Annual Technical Progress Report, 22 May 1999--21 August 2000

This report describes work being performed to provide details of the microstructure in high-quality hydrogenated amorphous and microcrystalline silicon and related alloys on the nanometer size scale. The materials under study are being prepared by current state-of-the-art deposition methods, as well as by new and emerging deposition techniques. The purpose is to establish the role ofnanostructural features in controlling the opto-electronic and photovoltaic properties. The approach centers around the use of the uncommon technique of small-angle scattering of both X-rays (SAXS) and neutrons (SANS). SAXS has already been established as highly sensitive to microvoids and columnar-like microstructure. A major goal of this research is to establish how sensitive SANS is to thehydrogen nanostructure. Conventional X-ray diffraction techniques are being used to examine medium-range order and microcrystallinity, particularly near the boundary between amorphous and microcrystalline material.