Light emission from silicon with tin-containing nanocrystals

Abstract

Tin-containing nanocrystals, embedded in silicon, have been fabricated by growing an epitaxial layer of Si_{1-x-y}Sn_{x}C_{y}, where x = 1.6 % and y = 0.04 %, followed by annealing at various temperatures ranging from 650 to 900 degrees C. The nanocrystal density and average diameters are determined by scanning transmission-electron microscopy to ~ 10^{17} cm^{-3} and ~ 5 nm, respectively. Photoluminescence spectroscopy demonstrates that the light emission is very pronounced for samples annealed at 725 degrees C, and Rutherford back-scattering spectrometry shows that the nanocrystals are predominantly in the diamond-structured phase at this particular annealing temperature. The origin of the light emission is discussed.Comment: 5 pages, 3 figures, submitted to AIP Advance

Light emission from silicon containing Sn-nanocrystals

“…A detailed description of the sample preparation is given in [6]. In short the Sn-nanocrystal samples were prepared by molecular-beam epitaxy, where a composite layer with ratios of 1.6 % Sn and 0.04 % C where co-deposited with Si.…”

“…in order to form the nanocrystals. From scanning transmission electron microscopy measurements it is know that annealing in that temperature range results in Sn-nanocrystal formation [6], as exemplified in Fig. 1.…”

“…A remarkably strong and rather broad luminescence feature is observed around 0.82 eV from the sample annealed at 725 • C. The center emission energy differs for the different annealing temperatures and even though part of the spectra extends below the detection limit of 0.76 eV, it is evident that the most luminescent sample is the one annealed at 725 • C. We observe this luminescence peak from low temperatures up to roughly 150 K. The crystal structure of the Sn-nanocrystals was investigated by Rutherford backscattering spectrometry using He ions. Comparing the yield of back-scattered ions under random incidence angles and under channeling conditions it is possible to extract the fraction of substitutional Sn atoms, i.e., atoms located on lattice sites corresponding to the diamond-structured host Si lattice (for more details, see [6]). This fraction is shown in Fig.…”

(Si)GeSn nanostructures for light emitters

“…There are several ways to create QDs, from direct over-growth on template substrates to controlled diffusion and segregation 22,23 . The low solubility of Sn in Ge can be used for QDs formation by simply annealing the GeSn layers, which causes the precipitation of Sn 24 .…”

Electronic structure calculation of Si1−xSnx compound alloy using interacting quasi‐band theory

“…While fabrication of Si‐based direct‐gap materials has been the most widely used approach for the realizing the desired on‐chip interconnectivity, fabrication of such materials has faced many challenges. Due to their same number of valence electrons as silicon, group‐IV compound alloys are attracting considerable attention . Among these materials, Si 1− x Sn x alloy is a promising candidate for the realizing on‐chip interconnectivity devices because its expected energy gap (0.75–0.95 eV) is favorable for optical communications due to the lack of absorption of the photons at this energy by the Si substrate .…”