Ultrafast infrared experiments in a-Si:H are presented on Si-H vibrations grown by plasma enhanced chemical vapor deposition and hot-wire techniques, in the temperature regime between 10 and 300 K. Non-exponential population decay of the stretching mode is observed, with a mean time constant ranging from 30 to 100 ps. At low temperatures (~15 K) the phase relaxation is limited by the population decay, but speeds up at high temperatures and becomes a single exponential. The phase relaxation depends on the power of the laser. We discuss the results in terms of a model in which the stretching mode is localized and decays into three bending modes and one TA phonon.

J. Non-Cryst. Solids

van der Voort, M., Rella, C. W., van der Meer, A. F. G., Akimov, A. V., & Dijkhuis, J. I. (2000). Ultrafast infrared experiments on Si-H vibrations in a-Si:H. J. Non-Cryst. Solids, 266-269, 180–184.