Boron-doped amorphous silicon layers deposited by glow-discharge on co
nductive substrates have been electrochemically etched in the same hyd
rofluoric acid solutions that yield intense visible light-emitting por
ous layers from crystalline silicon. We show that both as-etched and e
lectro-oxidized a-Si:H films are luminescent at room temperature in th
e visible and near infrared and we report electroluminescence spectra
recorded during the anodic oxidation. The room-temperature photolumine
scence decay times of a few tens of ys are longer at larger emission w
avelengths and comparable to those of porous wafers obtained in the sa
me way. In both cases, the decay pattern is shown to be qualitatively
distinct from that observed in amorphous silicon-based alloys.