The optical response above the band gap of light emitting porous silicon, as investigated by photoacoustic spectroscopy G. Amato, G. Spagnolo, L. Boarino, R. Gavioso and G. Benedetto J. Phys. IV France, 04 C7 (1994) C7-125-C7-128 DOI: 10.1051/jp4:1994730