Diener, J. and Ben-Chorin, M. and Kovalev, D. and Ganichev, Sergey and Koch, F.
Light from Porous Silicon by Multiphoton Vibronic Excitation.
Physical Review B 52 (12), R8617-R8620.
Other URL: http://www.physik.uni-regensburg.de/forschung/ganichev/reprints/PRB_Rapid1995_porous_silicon.pdf, http://prola.aps.org/abstract/PRB/v52/i12/pR8617_1
We study the emission of photons from porous Si after high-level vibrational excitation in the Si-O absorption band using a pulsed CO2 laser. Narrow resonances in the efficiency of light generation are discovered at 1030 and 1084 cm-1. Time-resolved experiments on the luminescence and the ir-induced changes in optical transparency show that the two excitation modes are characterized by different temporal responses. Additionally, their spectral distributions differ substantially. For excitation at 1030 cm-1 the familiar photoluminescence band of porous Si appears. We suggest microscopic processes responsible for the light emissions.