Mid-infrared pump–probe spectroscopy of Si–H stretch modes in porous silicon

Abstract

Using the Dutch free electron laser FELIX, we have investigated vibrational relaxation in free standing porous silicon (p-Si) films. Pump-probe measurements resonant with the SiH, SiH 2 and O 3 SiH stretching modes yield temperature dependent measurements of the decay rates which demonstrate that all the modes decay via at least one internal defect mode with the excess vibrational energy distributed among the Si-Si bath phonons in a fourth order decay process.

Photoluminescence analysis for terbium β-diketonate complex-based silica xerogel matrices

“…The peaks related to the (O-C) stretching vibration band are observed at 1250.09 and 1303.8 cm -1 [25]. The (O-H) and…”

“…The most important result from this FTIR spectrum is the existence of three bands. The first one at 1260.2 cm -1 is due to the vibrations of (Si-CH 3 ) bond [25], whereas the others at 2123.9 and 2263.5 cm -1 can be assigned to the presence of (Si-H) groups [27]. The appearance of these new bands as well as some of Tb complex functional groups, such as Tb-O and C-F vibrational bonds, may give as primary indication that the complex structure is not totally altered but partially over the heat treatment.…”

Combined pyrolysis-ammonolysis treatment to retain C during nitridation of SiBOCN ceramics

“…20) This former signal is still present at 1173 K but disappears when the pyrolysis temperature increases. This temperature was selected for switching atmospheres in the combined pyrolysis-ammonolysis treatment.…”