Structural and Optical Properties of Ge1-XSnx Alloys Grown on GaAs (001) by R. F. Magnetron Sputtering

Tuesday, 7 October 2014
Expo Center, 1st Floor, Center and Right Foyers (Moon Palace Resort)
H. Pérez Ladrón de Guevara (Universidad de Guadalajara), A. G. Rodríguez, H. Navarro-Contreras, and M. A. Vidal (Universidad Autónoma de San Luís Potosí)
Ge1-xSnx alloys were grown on GaAs (001) substrates in a conventional R. F. magnetron sputtering system with two independent plasmas not simultaneous focus to substrate. We determined the in-plane and in-growth lattice parameters for different Sn concentrations by high resolution X-ray diffraction (HRXRD). We observed that Ge1-xSnxlayers with low Sn concentrations have pseudomorphic characteristics. But this layers relax at Sn concentrations higher than the ones growth on Ge (001) substrates.

We also determined the band gap transitions and we found that the indirect-direct band gap crossover occurs as is predicted in Ge1-xSnx alloys growth on Ge (001). Raman spectroscopy confirms the presence and Sn concentrations of the Ge1-xSnx layers.