Photoluminescence spectroscopy and fourier transform infrared study on nanostructured porous silicon / Syed Mohd Helmi Syed Jamaludin

This project is to study the influences of the chemical etching by low concentration hydrofluoric acid on porous silicon (PS) surfaces using photoluminescence spectroscopy (PL) and Fourier Transform Spectroscopy (FTIR). The PS surface was found to emit visible luminescence at room temperature. PL spectroscopy confirms the possibility of a quantum confinement effect by revealing the strong intensity and blue shift for the PS layer with chemical etching. We have characterized the FTIR peak of 620 cm¯ᶦ as the on- and near the surface regions of PS. The peak of 610 cm¯ᶦ is assigned for the Si - Si vibration mode in the bulk. The peaks present in the region of 2090 - 2140 cm¯ᶦ correspond to the Si - H, Si - H₂, and Si - H₃ stretching mode proof that the formulation of the Hydrogen band comes from HF. Also, the large bands in the 1000-1200 cm'1 range are generally assigned to Si-O-Si stretching modes and to the presence of surface oxide species. IR absorbance studies on the PS layers indicated that the identity of the surface molecule is immaterial to the enhancement or degradation of photoluminescence.