Porous silicon (PS) layers were formed on p-type, 〈100〉 oriented, 1–5Ωcm resistivity Cz silicon wafers by electrochemical etching in an HF:C 2 H 5 OH (1:2 by volume) electrolyte at room temperature at a constant current density 20mA/cm 2 . The etching duration was varied to achieve PS layers of different morphologies and thicknesses. Both the photoluminescence (PL) and the total diffused reflectivity spectra of the PS layers were measured. It was found that for the PS layers grown for etching durations of less than 90s the PL emission is insignificant and reflectivity is quite low. Such PS layers can be used as antireflection coatings (ARC) on solar cells. The PS layers formed for etching durations greater than 90s show a significant PL emission in 500–800nm range with peak lying in 630–660nm wavelength range. When etching duration increases from 90s to 8min the PL intensity increases and the PL peak shows a blue shift. With further increase in etching duration the PL intensity decreases and PL peak shows a red shift. The reflectivity of the photoluminescent layers increases with etching duration showing a highest value for a sample grown for 8min. Further increase in etching duration up to 20min the reflectivity decreases and then increases. Striking observation is that both the PL emission intensity and reflectivity in the wavelength range of 550–800nm are maximum for the PS layer grown for the etching duration of 8min.