arXiv Analytics

Sign in

arXiv:1904.07201 [cond-mat.mtrl-sci]AbstractReferencesReviewsResources

Mid-infrared (3-8 μm) $\text{Ge}_{1-y}\text{Sn}_y$ alloys (0.15 < $y$ < 0.30): synthesis, structural, and optical properties

Chi Xu, Patrick M. Wallace, Dhruve A. Ringwala, Shery L. Y. Chang, Christian D. Poweleit, John Kouvetakis, José Menéndez

Published 2019-04-15Version 1

$\text{Ge}_{1-y}\text{Sn}_y$ alloys with compositions in the 0.15 < $y$ < 0.30 range have been grown directly on Si substrates using a chemical vapor deposition approach that allows for growth temperatures as high as 290 $^{\circ}$C. The films show structural properties that are consistent with results from earlier materials with much lower Sn concentrations. These include the lattice parameter and the Ge-Ge Raman frequency, which are found to depend linearly on composition. The simplicity of the structures, directly grown on Si, makes it possible to carry out detailed optical studies. Sharp absorption edges are found, reaching 8 $\mu$m near $y$ =0.3. The compositional dependence of edge energies shows a cubic deviation from the standard quadratic alloy expression. The cubic term may dramatically impact the ability of the alloys to cover the long-wavelength (8-12 $\mu$m) mid-IR atmospheric window.

Related articles: Most relevant | Search more
arXiv:1206.2160 [cond-mat.mtrl-sci] (Published 2012-06-11, updated 2012-06-26)
Elastic, thermodynamic, electronic and optical properties of U2Ti
arXiv:cond-mat/9811306 (Published 1998-11-20)
Effects of disorder on the optical properties of the (Zn,Mg)(S,Se) quaternary alloy
arXiv:cond-mat/0405097 (Published 2004-05-05)
Optical properties of Mn4+ ions in GaN:Mn codoped with Mg acceptors