Photoluminescence and photoelectrical study on plasma-modified porous silicon (PS) thin films is presented. Porous silicon passivated by hydrocarbon groups (CHx) shows an intense broad and stable photoluminescence (PL) band centered at 623 nm whereas the maximum of the photosensitivity spectrum is placed around 400 nm. Along with its potential utilization for silicon-based light emitters' fabrication, it could also represent an appealing option for the improvement of energy conversion efficiency in silicon-based solar cells whether by using its luminescence properties (photon down-conversion) or the excess photocurrent produced by an improved high-energy photon's absorption. Excitation spectra (PLE) under steady-state conditions are reported. PLE shows that visible PL is excited by light from UV region. The time-resolved photoluminescence of CHx/PS in the range of some tenth of mu s are investigated at room temperature. The PL decay line shape, in CHx/PS is well described by stretched exponential. The photosensitivity spectroscopy shows a significant increase of absorption at high photon energy excitation. (C) 2013 Elsevier B.V. All rights reserved.