Influence of the annealing treatments on the luminescence properties of SiO∕SiO2 multilayers

O. Jambois, H. Rinnert, X. Devaux, M. Vergnat
2006 Journal of Applied Physics  
The formation of silicon nanocrystals ͑Si-ncs͒ and their room temperature photoluminescence ͑PL͒ properties were investigated in samples elaborated by the evaporation method. Silicon oxide ͑SiO͒ single layer and SiO / SiO 2 multilayers with different SiO layer thicknesses from 1 to 5 nm were prepared and annealed at different temperatures up to 1050°C. The structure and the formation of Si-nc were studied by transmission electron microscopy ͑TEM͒ and by Fourier transform infrared ͑FTIR͒
more » ... on spectroscopy. It is demonstrated that the Si-ncs appear by the phase separation process from SiO due to the annealing treatments. Contrary to the SiO single layer, the multilayers are a powerful system to obtain highly luminescent Si-nc and to control the Si-nc size for SiO layer thicknesses lower than or equal to 4 nm. It is clearly shown that, in agreement with the quantum confinement theory, the PL energy is a decreasing function of the Si-nc size. However, thanks to the correlation between FTIR, TEM, and PL results, it is demonstrated that the PL energy is also strongly dependent on the quality of the matrix in which the Si-nc are embedded. A model based on the existence of a SiO x shell surrounding the Si-nc is proposed to explain the PL results.
doi:10.1063/1.2402976 fatcat:5mtvdkm425fp7pyehu23aorqia