Structural and optical properties of light emitting nanocrystalline porous silicon layers

This paper reports the structural and optical properties of as-anodized porous silicon layers obtained by electrochemical etching By keeping the constant etching time and HF concentration, two samples S1 and S2 were prepared at distinct current density The prepared samples showed distinct color distribution over the entire surface of porous silicon Red band emission from nanocrystalline porous silicon layers were observed at centered wavelength 630 and 670nm Our results showed that the porous silicon luminescence is due to the presence of surface confined molecular emitters i.e siloxene Raman peak observed at 520.5cm(-1) from both samples S1 and S2 indicates the less possibility of quantum confinement effect Atomic force microcopy measurements showed that the prepared samples consist of inhomogeneous and irregular shaped pore and air voids randomly distributed over the entire surface