SixGe1-x alloy as efficient phonon barrier in Ge/Si superlattices for thermoelectric applicationsRiccardo Dettori, Claudio Melis and Luciano ColomboEur. Phys. J. B, 88 1 (2015) 27DOI: https://doi.org/10.1140/epjb/e2014-50628-8