Nanostructure of a-Si:H and Related Alloys by Small-Angle Scattering of Neutrons and X-Rays: Annual Technical Progress Report, 22 May 1998 - 21 May 1999

This report describes work being performed to provide details of the microstructure in high-quality hydrogenated amorphous silicon and related; alloys on the nanometer scale. The materials under study are being prepared by state-of-the-art deposition methods, as well as by new and; emerging deposition techniques. The purpose is to establish the role of nanostructural features in controllingopto-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 the sensitivity of SANS to the hydrogen nanostructure. ConventionalX-ray diffraction techniques are being used to examine medium-range order and microcrystallinity, particularly near the boundary between amorphous and microcrystalline material.