Parametrized dielectric functions of amorphous GeSn alloys

Autor:	Daniel Schmidt, Wei Wang, Vijay Richard D'Costa, Yee-Chia Yeo
Rok vydání:	2015
Předmět:	Ion implantation Materials science Kramers–Kronig relations Condensed matter physics Band gap Ellipsometry Dispersion (optics) General Physics and Astronomy Dielectric Amorphous solid Molecular beam epitaxy
Zdroj:	Journal of Applied Physics. 118:123102
ISSN:	1089-7550 0021-8979
DOI:	10.1063/1.4931435
Popis:	We obtained the complex dielectric function of amorphous Ge1−xSnx (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge0.75Sn0.25 and Ge0.50Sn0.50 alloys from literature. The compositional dependence of band gap energy Eg and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::61eb966bc8d8efc78a2070fb5470f251 https://doi.org/10.1063/1.4931435 Zobrazit plný text záznamu