Enhancement of porous silicon photoluminescence by electroless deposition of nickel

Nickel-porous silicon nanocomposites (PS/Ni) are elaborated by an electroless deposition method using NiCl2 aqueous solution. The presence of nickel ions in the porous layer is confirmed by Fourier Transformed InfraRed spectroscopy (FTIR) and Raman spectroscopy. The photoluminescence (PL) spectra of PS/Ni, prepared at different electroless durations (tedp), are analyzed. A remarkable enhancement in the integrated PL intensity of PS containing nickel was observed. The lower tedp favor the deposition of nickel in PS, hence the silicon dangling bonds at the porous surface are quenched and this was increased the PL intensity. However, for the longer tedp, the PL intensity has been considerably decreased due to the destruction of some Si nanocrystallites. The PL spectra of PS/Ni, for tedp less than 8 min, show a multiband profile indicating the creation of new luminescent centers by Ni elements which induces a strong modification in the emission mechanisms.