Quantifying the Short-Range Order in Amorphous Silicon by Raman Scattering

• Published in: Analytical chemistry (Washington) Vol. 90; no. 13; pp. 8123 - 8129
• Main Authors: Yogi, Priyanka, Tanwar, Manushree, Saxena, Shailendra K, Mishra, Suryakant, Pathak, Devesh K, Chaudhary, Anjali, Sagdeo, Pankaj R, Kumar, Rajesh
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 03-07-2018
• Subjects: Amorphous silicon; Chemistry; Confinement; Empirical analysis; Line spectra; Nanocrystals; Raman spectra; Shape functions; Short range order; Silicon
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.8b01352

Quantification of the short-range order in amorphous silicon has been formulized using Raman scattering by taking into account established frameworks for studying the spectral line-shape and size dependent Raman peak shift. A theoretical line-shape function has been proposed for representing the observed Raman scattering spectrum from amorphous-Si-based on modified phonon confinement model framework. While analyzing modified phonon confinement model, the term “confinement size” used in the context of nanocrystalline Si was found analogous to the short-range order distance in a-Si thus enabling one to quantify the same using Raman scattering. Additionally, an empirical formula has been proposed using bond polarizability model for estimating the short-range order making one capable to quantify the distance of short-range order by looking at the Raman peak position alone. Both the proposals have been validated using three different data sets reported by three different research groups from a-Si samples prepared by three different methods making the analysis universal.