Luminescent silicon nanocrystal dots fabricated by SiCl4/H2 RF plasma-enhanced chemical vapor deposition

Luminescent nanocrystalline Si dots were fabricated directly on thermally grown SiO2 at 120°C by conventional RF plasma-enhanced chemical vapor deposition using tetrachlorosilane, SiCl4 and H2. As-deposited Si dot exhibits photoluminescence (PL) in the visible region, consisting of two broad bands corresponding to photon energies of 1.38 and View the MathML source. Storage in air enhances PL and shifts the PL peak energy to higher wavelengths for dots of diameter less than View the MathML source. Fourier transform attenuated total reflection absorption spectroscopy (FTIR-ATR) study reveals that the spontaneous oxidation proceeds until saturation after View the MathML source at dot sizes of 3–View the MathML source. The relationship between PL intensity, blueshift of PL peak energy, and surface termination species during oxidation indicates that these changes are attributed to the increased density of radiative centers at the Si nanocrystal dot/SiO2 interface and enhancement of the quantum confinement effect.