No CrossRef data available.
Published online by Cambridge University Press: 31 January 2011
In this paper, we present a systematic study of coherent phonons in Si/SiGe superlattices with two different periods. The superlattice periodicity affects the acoustic properties of the structure. Transient thermoreflectance (TTR) technique is used to perform picosecond ultrasonics experiments and then, investigate coherent zone-folded acoustic phonons in different Si/SiGe superlattice structures. Several classes of coherent phonons are produced in the superlattice, whose generation mechanisms are different: Brillouin oscillations, coherent longitudinal-acoustic phonon Bragg reflection and impulsive stimulated Raman scattering (ISRS).