J. Phys. Colloques
Volume 47, Numéro C8, Décembre 1986EXAFS and Near Edge Structure IV
|Page(s)||C8-349 - C8-356|
J. Phys. Colloques 47 (1986) C8-349-C8-356
X-RAY ABSORPTION STUDIES OF AMORPHOUS SEMICONDUCTORSD.E. SAYERS et M.A. PAESLER
Department of Physics, N.C. State University, Raleigh, NC 27695-8202, U.S.A.
Two families of amorphous (a-) semiconductors are chosen to demonstrate current state-of-the-art techniques in x-ray absorption spectros copy (XAS). We first briefly review recent developments in XAS methods before limiting the discussion to tetrahedrally co-ordinated films (a-Si, a-Ge, and a-SixGe1-x:H with 0 < x < 1) and arsenic trisulfide (a-As2S3). The phenomenon of crystallization of a-Si and a-Ge as well as the ordering of these elemental a-semiconductors prior to the nucleation of microcrystallites is discussed in terms of XAS experiments. We review XAS studies of the role of H in determining the structure of a-SixGe1-x:H. Investigations of XAS on a-As2S3 are shown to result in : (1) an ability to use XAS to measure bond strengths ; (2) a better understanding of reversible photodarkening ; and, (3) development of a technique for crystallizing pure bulk As2S3 glass.