Optics and Photonics Society of Iran

Silicon nanowires are fabricated through one step metal assisted chemical etching method with different etching times (30, 60, and 80 min). According to FESEM images SiNWs arrays are dens, ordered and vertical to the wafer surface. While with increasing the etching time from 30 to 60 min the lengths of nanowires are increased and their diameters are decreased; with continuing the process to 80 min their lengths are reduced. Using reflectance spectra and Kubelka–Munk equation we have calculated the optical band gap of the samples. We found with increasing the etching time, due to quantum confined effect, the band gap is increased from 1.36 eV to 1.58 eV. These variations could be useful in photodetectors.