Strong white and blue photoluminescence from silicon nanocrystals in SiN_xgrown by remote PECVD using SiCl₄/NH₃

Abstract

Strong white and blue photoluminescence (PL) from as-grown silicon nanocrystals (nc-Si) in SiNx films prepared by remote plasma enhanced chemical vapour deposition using SiCl4/NH3 mixtures is reported. The colour and intensity of the PL could be controlled by adjusting the NH3 flow rate. Samples with white emission were annealed at 1000 °C, obtaining a strong improvement of the PL intensity with a blue colour. The PL can be attributed to quantum confinement effect in nc-Si embedded in SiNx matrix, which is improved when a better passivation of nc-Si surface with chlorine and nitrogen atoms is obtained. The size, density and structure of the nc-Si in the as-grown and annealed films were confirmed and measured by high-resolution transmission electron microscopy.

Structural and optical properties of 70-keV carbon ion beam synthesized carbon nanoclusters in thermally grown silicon dioxide

“…The PL peak energy positions in the 30-min and 1-h annealed samples are almost similar to narrower FWHM for increased annealing time. The intensity of the 2.8 eV band increased drastically for the sample annealed for 1 h. Similar multiple PL peaks have been observed from Cl-and N-passivated silicon nanocrystals embedded in PECVD grown silicon nitride thin films [31], when the samples were excited by a 325-nm HeCd laser. Benami et al [31] also reported a similar intense luminescence peak at 2.8 eV in a sample annealed at 1,000°C.…”

Enhancement and quenching of photoluminescence from silicon quantum dots by silver nanoparticles in a totally integrated configuration

“…• C. The energy RBS signal of the 4 He +2 ions backscattered by the Ag atoms can be observed in the 2235-2577 keV energy range, with a maximum at 2378 keV. For comparison, we can mention that the energy of the 4 He +2 ions backscattered by Ag atoms at the surface of the sample would correspond to 2590 keV, indicating that the Ag NPs are really deep embedded in the silica matrix.…”

“…For comparison, we can mention that the energy of the 4 He +2 ions backscattered by Ag atoms at the surface of the sample would correspond to 2590 keV, indicating that the Ag NPs are really deep embedded in the silica matrix. As the RBS technique does not allow distinguishing an element from two different sources, the silicon signal due to the Si QDs is veiled by the silicon signal due to the matrix.…”

“…1, 2 Observation of intense visible photoluminescence and electroluminescence at room temperature and optical gain in Si QDs indicate their potential for optoelectronic applications; [3][4][5][6] however, Si QDs show low internal quantum efficiency and radiative decay rates compared to direct band gap semiconductors, as a consequence of the competition between quasi-direct and indirect recombination. To overcome this limitation, the integration of plasmonic materials in the form of metallic nanoparticles or metallic thin films to the semiconductor containing the Si QDs has been used in the last decade.…”

“…Besides, it has been well established that metallic nanoparticles, such as Ag and Au, support surface plasmon resonance (SPR), which can be tuned throughout the UV-vis-near-IR spectrum by controlling their shape, size and their local dielectric environment. [12][13][14][15] There are many ways to fabricate nanocrystalline silicon, such as plasma enhanced chemical vapor deposition (PECVD), remote-PECVD (RPECVD), 4,16,17 implantation. 6,18,19 In this work we have used the ion implantation technique to obtain a totally integrated configuration formed by Si QDs and silver nanoparticles (Ag NPs).…”