Nanostructure of a-Si:H and Related Alloys by Small-Angle Scattering of Neutrons and X-Rays: Final Technical Progress Report, 22 May 1998 - 15 October 2001

This report describes work 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 studied were 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 of nanostructural features incontrolling the opto-electronic and photovoltaic properties. The approach centered 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 was to establish the ability of SANS to detect hydrogen inhomogeneity indevice-quality materials. This was demonstrated and new information on various materials have been provided. Conventional X-ray diffraction techniques were used to examine medium-range order and microcrystallinity, particularly near the boundary between amorphous and microcrystalline material.