Ultrafast vibrational dynamics and stability of deuterated amorphous silicon.
Infrared four-wave mixing experiments performed upon deuterated amorphous silicon layers (a-Si:D) reveal profound differences in the dynamics of Si-D stretch vibrations compared to those of analogous Si-H vibrational modes in hydrogenated amorphous silicon (a-Si:H). Remarkably, transient-grating measurements of the population decay rate of the Si-D vibrations show single-exponential decay directly into collective modes of the a-Si host, bypassing the local bending modes of the defect into which the Si-H vibrations decay. Photon-echo measurements of the vibrational dephasing suggest at low temperature contributions from TO nonequilibrium phonons and at elevated temperatures elastic phonon scattering of TA phonons.
Wells
Jon-Paul R
JP
Felix Free Electron Laser Facility, FOM-Institute for Plasmaphysics "Rijnhuizen," P.O. Box 1207, 3430 BE, Nieuwegein, The Netherlands.
Schropp
Ruud E I
RE
van der Meer
Lex F G
LF
Dijkhuis
Jaap I
JI