abstract

• The optical energy gap of Ge1-x Snx alloys (x≤0.14) grown on Ge substrates has been determined by performing transmittance measurements at 4 K using a fast fourier transform infrared interferometer. The direct energy gap transitions in Ge1-x Snx alloys behave following a nonlinear dependence on the Sn concentration, expressed by a quadratic equation, with a so called bowing parameter b0 that describes the deviation from a simple linear dependence. Our observations resulted in b0RT =2.30±0.10 eV and b0 4 K =2.84±0.15 eV, at room temperature and 4 K, respectively. The validity of our fit is limited for Sn concentrations lower than 15%25. © 2007 American Institute of Physics.

authors

• Navarro Contreras Hugo Ricardo
• Pérez Ladrón De Guevara H.
• Rodríguez Vázquez Ángel Gabriel
• Vidal Borbolla Miguel Angel

publication date

• 2007-01-01

funding provided via

• Consejo Nacional de Ciencia y Tecnología, CONACYT  Grant

published in

• Applied Physics Letters  Journal

keywords

• Energy gap; Nonlinear optics; Tin; Fourier transform infrared interferometer; Quadratic equations; Room temperature; Germanium alloys

Digital Object Identifier (DOI)

• 10.1063/1.2800296

start page

end page

volume

• 91

issue

• 16