The effect of size and depth profile of Si-nc imbedded in a SiO2 layer on the photoluminescence spectra

Abstract It has been demonstrated that the size and depth profile of silicon nanocrystals produced by implanting Si + ions (∼100 keV) into SiO 2 are dependent on the implantation dose. Here, we demonstrate that these parameters have, in turn, a significant effect on the photoluminescence (PL) spectra of Si-nc imbedded in a thin SiO 2 layer formed on a silicon backing. Strong spectral modulation is observed compared with the PL spectra of Si-nc imbedded in bulk SiO 2 for implantation doses of 6×10 16 , 8×10 16 and 1×10 17 Si + /cm 2 , whereas for an implantation dose of 3×10 17 Si + /cm 2 , very little spectral deformation is noted. The modulation in the luminescence spectrum is caused by optical interference effects produced by the layered structure. Two types of optical interference must be considered: the pump laser standing wave, which determines the pump amplitude as a function of depth in the SiO 2 layer, and the optical interference of the Si-nc luminescence, which is a function of the depth of the Si-nc in the SiO 2 layer. Such modulation in a layered structure can serve to tailor the Si-nc luminescence spectrum for specific applications.