Local atomic configurations, energy structure, and optical properties of implantation defects in Gd-doped silica glass: An XPS, PL, and DFT study

• Published in: Journal of alloys and compounds Vol. 796; pp. 77 - 85
• Main Authors: Zatsepin, A.F., Zatsepin, D.A., Boukhvalov, D.W., Kuznetsova, Yu.A., Gavrilov, N.V., Shur, V. Ya, Esin, A.A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.08.2019; Elsevier BV
• Subjects: Atomic structure; Charge transfer; Defects; DFT; Electronic structure; Energy costs; Gadolininia; Gadolinium; Implantation; Impurities; Interstitials; Optical properties; Oxides; Passivity; Photoelectrons; Photoluminescence; Silica; Silica glass; Silicon dioxide; X ray photoelectron spectroscopy; DFT; Impurities; Gadolininia; Photoluminescence; Implantation; Oxides; Silica
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.04.303

The KUVI-SiO2 hosts were Gd-implanted and passivated using Bonilla's stable passivation conditions. Their electronic structure was studied employing X-ray Photoelectron (XPS) and Photoluminescence (PL) spectroscopies with the onward theoretical DFT-modeling of experimentally derived scenarios for pulsed Gd-implantation into amorphous matrix. Both experiment and theory report the unfavorability of substitutional Gd-defects formation. The most probable scenario of Gd accumulation in the host-structure is Gd-interstitials with the fabrication of ≡Si–O–[Gd]3+… clusters with partial location of Gd atoms in the vicinity of Si ODC's. Tempering reduces the Nomura's bonds-switching charge-transfer mechanism in the electronic structure of KUVI-SiO2:Gd and, with a high probability, leads to fabrication of Si QDs, which have been well recognized by the PL-technique. DFT calculations confidently demonstrate relatively low energy costs required for oxygen passivation by embedded Gd and the fabrication of Si-Si bonds inside the host. •Gadolinium doped silica have been studied experimentally and theoretically.•Implanted gadolinium ions prefer to occupy interstitial positions.•Formation of interstitial Gd-impurities does not change valence bands specters.•During annealing occurs oxidation of gadolinium impurities and formation of Si-clusters.