Abstract
We present results of pump-probe anti-Stokes Raman experiments at 1.8 K on the generation of nonequilibrium phonons in a-Si:H following intense optical excitation. We obtained a decay time of ∼70 ns for the TO phonons in all samples studied. In plasma deposited samples we observed an additional slowly decaying ( ⪢100 ns ) contribution to the Raman signal, which was not seen in hot-wire deposited samples. We propose a model to explain the additional phonons as resulting from fast nonradiative recombination of free carriers with carriers localized in the tail states.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have