Sn-loss effect in a Sn-implanted a-SiO2 host-matrix after thermal annealing: A combined XPS, PL, and DFT study

Abstract

Amorphous a-SiO 2 host-matrices were implanted with Sn-ions with and without posterior thermal tempering at 900 °С for 1 hour in ambient air. X-ray photoelectron spectroscopy analysis (XPS core-levels, XPS valence band mapping), photoluminescence (PL) probing, and density functional calculations (DFT) were employed to enable a detailed electronic structure characterization of these samples. It was experimentally established that the process of Snembedding into the a-SiO 2 host occurs following two dissimilar trends: the Sn 4+ →Si 4+ substitution in a-SiO 2 :Sn (without tempering), and Sn-metal clustering as interstitials in a-SiO 2 :Sn (900 °С, 1 hour). Both trends were modeled using calculated formation energies and partial densities of states (PDOS) as well as valence band (VB) simulations, which yielded evidence that substitutional defect generation occurs with the help of ion-implantation stimulated translocation of the host-atoms from their stoichiometric positions to the interstitial void.Experimental and theoretical data obtained coincide in terms of the reported Sn-loss effect in a-SiO 2 :Sn (900 °С, 1 hour) due to thermally-induced electronic host-structure re-arraignment, which manifests as backward host-atoms translocation into stoichiometric positions and the posterior formation of Sn-metal clusters.

Enhanced clustering tendency of Cu-impurities with a number of oxygen vacancies in heavy carbon-loaded TiO2 - the bulk and surface morphologies

“…On the first look the appearance of Cu 0 means Cu-losses from the ion-beam stimulated synthesis and modulation of Cx-TiO 2 microstructure (this effect was established earlier by the other researchers even for amorphous hosts [59,60] and in our previous findings [61,62]), but, what might be really interesting in our humble opinion, it is accompanied by embedded metal treating of oxygen vacancies (see, for instance, Ref. [63,64]), and this occurred one more time with the current samples even under sequential and relatively soft (regarding applied mode) ion-beam stimulated synthesis.…”

The Protection Role of Cysteine for Cu-5Zn-5Al-1Sn Alloy Corrosion in 3.5 wt.% NaCl Solution

“…The peaks centered at 486.65 eV, 486.77 eV, and 486.58 eV correspond to the Sn5/2 peaks, which were obtained in blank solution, with 10 −4 M Cys and with 10 −2 M Cys, respectively (Figure 7b). In all cases, the peak values correspond to ionic tin (Sn 4+ ) [39,[52][53][54][55][56], which may indicate the formation of the compound of Sn on the alloy surface, meaning, therefore, the contribution of Sn 2+ to the surface film should not be ignored. In addition to the main Sn3d peaks, satellite peaks at higher binding energies of 499.05 and 499.08 eV appear for the blank and the surface-inhibited surface with lower Cys concentration (10 −4 M), respectively, which may be attributed to the presence of more tin ion contents on the alloy surface [57].…”

Structural Evolution and Photoluminescence of SiO2 Layers with Sn Nanoclusters Formed by Ion Implantation

“…At present, adding optical functionality to a silicon microelectronic chip is one of the most challenging problems of materials research. Thereby, considerable efforts have been focused on the enhancement of UV and visible emission from silica to create an active lightemitting element in next-generation miniature optoelectronic devices [1][2][3][4][5][6][7][8][9][10][11][12]. In spite of typical optoelectronic's operation in IR range, the creation of such silica-based emitters operating in both the visible and UV-violet spectral ranges is a perspective for creating a microminiature MOS light-emitting diode (LED), Bragg reflectors, waveguide lasers, and optocouplers as well as optical switchers in color microdisplay devices.…”

“…In spite of typical optoelectronic's operation in IR range, the creation of such silica-based emitters operating in both the visible and UV-violet spectral ranges is a perspective for creating a microminiature MOS light-emitting diode (LED), Bragg reflectors, waveguide lasers, and optocouplers as well as optical switchers in color microdisplay devices. To fabricate a low-cost effective silicabased LED, the ion implantation approach seems quite promising because of well-controlled impurity atom distribution and/or impurity-based nanocrystal formation, good passivation from ambient condition, and excellent compatibility with Si MOS processes [1][2][3][4][10][11][12].…”

“…Considering the complicated phase composition as well as the presence of different radiative and nonradiative centers in Sn-implanted films, the deep analysis of structural and luminescence properties depending on the regime of implantation and subsequent annealing is needed. In spite of a number of publications devoted to silicon oxide films implanted with Sn ions [1][2][3][4][10][11][12], the influence of implantation fluence on their structure and luminescence was studied insufficiently. In this paper, we report the structural and light-emitting properties of "SiO 2 +Sn-based NC" composites created by means of Sn + implantation with two different fluences into SiO 2 on Si followed by oxidation in ambient air.…”