Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• emission properties were studied by photoluminescence spectroscopy under excitation at 325 nm. It was found that annealing at 500 °C leads to the production of macroscopically homogeneous wurtzite phase films, while thermal treatment at higher or lower temperature results in the degradation of the

• deposited by spin coating and subjected to post-deposition annealing at 400 °C and 500 °C is similar. However, the morphology degrades for films annealed at temperatures higher than 600 °C. Figure 2 compares the surface morphology of films prepared by aerosol spray pyrolysis and spin coating annealed at 500

• . At the same time, the annealing of films at 650 °C (see Figure 2c) leads to deterioration of the morphology resulting in numerous cracks. We suppose that the difference in roughness of films prepared by the two methods is determined by the specific features of the technology. Namely, the deposition

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• molecules into the Sn-down conformation was observed either after sample annealing at 200 °C or as a result of tip-induced manipulation. Room-temperature measurements conducted for a coverage of close to a monolayer showed no tendency for molecular arrangement. Keywords: rutile (110) surface; scanning

• the position of a tin atom protruding from the macrocycle: “Sn-up” and “Sn-down”. Switching from the Sn-up to the Sn-down geometry can be realized by annealing the sample at 200 °C or by tip-induced manipulation (bias pulse). X-ray photoelectron spectroscopy (XPS) measurements reveal a lack of strong

• prepared by repetitive cycles of Ar+-ion bombardment at an energy of 1 keV and subsequent annealing to a temperature of 700 °C. Tin phthalocyanine molecules (Tokyo Chemical Industry Co., Ltd.) were thermally evaporated by using an effusion cell (Kentax GmbH). After prudent degassing, the deposition flux

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

• Wael M. Mohammed,
• Igor V. Yanilkin,
• Amir I. Gumarov,
• Airat G. Kiiamov,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2020, 11, 807–813, doi:10.3762/bjnano.11.65

• , Germany). LEED images were taken of the pristine MgO(001) substrate after annealing (Figure 1a), after the deposition of VN(30 nm) on MgO (Figure 1b), after the deposition of Pd0.92Fe0.08 on VN (Figure 1c) and after the deposition of VN on Pd0.96Fe0.04 (Figure 1d). Figure 1b indicates that the individual

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• brightest SPSs observed in any material at room temperature. Similarly, bulk BN was studied by [100] after annealing the sample in Ar at 850 °C for 30 min and at 0.5 Torr to increase the concentration of defects with similar ZPLs previously reported. However, they were found to photo-bleach with excitation

• density of emitters. Such methods based on high-temperature annealing in air and ultraviolet ozone processing are effectively used to improve SP purity (g(2)(0) ≤ 0.1) and the linewidth (FWHM room temperature of ≈3 nm) of the ZPL of CVD-grown h-BN [108]. By control of the boron diffusion through copper

• with 10 keV gallium ions at a dose of 10−14 C/µm2 with subsequent annealing with argon at 1 Torr and 750 °C for 30 min. The lifetime, brightness, and PL stability of this SPE are similar to those in 2D h-BN, however with a wavelength variation smaller by a factor of five as compared to the SPEs in 2D h

Structural optical and electrical properties of a transparent conductive ITO/Al–Ag/ITO multilayer contact

• Aliyu Kabiru Isiyaku,
• Ahmad Hadi Ali and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2020, 11, 695–702, doi:10.3762/bjnano.11.57

• pure ITO layer (as reference) were prepared by RF and DC sputtering. The microstructural, optical and electrical properties of the ITO/Al–Ag/ITO (IAAI) films were investigated before and after annealing at 400 °C. X-ray diffraction measurements show that the insertion of the Al–Ag intermediate bilayer

• led to the crystallization of an Ag interlayer even at the as-deposited stage. Peaks attributed to ITO(222), Ag(111) and Al(200) were observed after annealing, indicating an enhancement in crystallinity of the multilayer films. The annealed IAAI film exhibited a remarkable improvement in optical

• × 10−3 Ω−1). These highly conductive and transparent ITO films with Al–Ag interlayer can be a promising contact for low-resistance optoelectronics devices. Keywords: annealing; DC sputtering; figure of merit; indium tin oxide (ITO); multilayer structure; RF sputtering; Introduction Transparent

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• residuals to synthesize carbon nanoparticles by hydrothermal carbonization (HTC), annealing at high temperature, and laser ablation (LA) in a NH4OH solution. The carbon nanoparticles synthesized with the HTC process (HTC-CDs) exhibit photoluminescent characteristics with strong blue emission. The annealing

• , which involves the HTC treatment, high-temperature annealing, and LAL processing, sequentially. The purpose of the LAL processing is to introduce N-containing functional groups onto the surface of carbon nanoparticles and to recover the PL of carbon nanoparticles/CDs that was quenched by the high

• -temperature annealing. Both methods can be categorized as top-down methods in contrast to bottom-up methods. The PL characteristics of the CDs produced by both methods are analyzed, and the PL mechanisms of the CDs are discussed. The strategies developed in this work offer simple and effective means for

Correction: Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2020, 11, 547–549, doi:10.3762/bjnano.11.43

• relating to Ag, although very low intensity peaks related to Ag were observed for the sample calcined at 600 °C [6]. In a previous work, it was found that the intensity of the anatase peaks decreased in comparison to the rutile peaks as the annealing temperature increased; and after annealing at 800 °C

Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions

• Robert Kozioł,
• Marcin Łapiński,
• Paweł Syty,
• Damian Koszelow,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2020, 11, 494–507, doi:10.3762/bjnano.11.40

• Narutowicza 11/12, 80-233 Gdansk, Poland 10.3762/bjnano.11.40 Abstract Ag-based plasmonic nanostructures were manufactured by thermal annealing of thin metallic films. Structure and morphology were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution

• transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). SEM images show that the formation of nanostructures is influenced by the initial layer thickness as well as the temperature and the time of annealing. The Ag 3d and Ag 4d XPS spectra are characteristic of nanostructures. The

• . However, in the case of very simple production methods, as wet chemical synthesis or dewetting, the size of the nanoparticles follows a Gaussian distribution. This work focusses on Ag-based plasmonic platforms manufactured by thermal annealing of thin metallic films. The experimental results are

Atomic-resolution imaging of rutile TiO₂(110)-(1 × 2) reconstructed surface by non-contact atomic force microscopy

• Daiki Katsube,
• Shoki Ojima,
• Eiichi Inami and
• Masayuki Abe

Beilstein J. Nanotechnol. 2020, 11, 443–449, doi:10.3762/bjnano.11.35

• .) were used. A rutile TiO2(110)-(1 × 2) reconstructed surface was prepared by iterating a surface cleaning process of Ar+ sputtering (2 keV, Ar partial pressure of 3.0 × 10−4 Pa, ion current of ca. 1.1 µA, 10 min) and annealing (substrate temperature of ca. 1000 °C, 30 min). STM and NC-AFM imaging was

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study

• Satheeshkumar Balu,
• Manisha Vidyavathy Sundaradoss,
• Swetha Andra and
• Jaison Jeevanandam

Beilstein J. Nanotechnol. 2020, 11, 285–295, doi:10.3762/bjnano.11.21

• in the crystallite size will lead to reduction in the mechanical properties of the Hap nanoparticles [36]. Moreover, Ooi et al. (2018) recently reported that a high annealing temperature will affect the porous structure of Hap nanoparticles [37]. In the present study, the TGA (Figure 3) shows 0

• % weight loss at 600 °C to form CB-Hap NRs due to the complete removal of organic substances and water. Thus, 700 °C is selected as the optimum annealing temperature for the formation of Hap NRs as suggested from previous studies. Morphology and elemental analysis TEM micrographs of CB-derived Hap nanorods

• after annealing which may be due to the removal of organic products such as collagen and protein. Chemicals and reagents Marine waste cuttlefish bones were collected as a source of calcium from Kasimedu fish market, which is located in Chennai, Tamil Nadu, India. All chemicals used for this study were

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• composite. ZIF-67 is processed into Co3O4 by an annealing process reported previously [32]. The resulting Co3O4 exhibits a nest-like structure and a porous morphology, and the dodecahedral structure is largely kept with no apparent collapse. The TEM image in Figure 2f clearly shows that the Co3O4 particles

Fabrication of Ag-modified hollow titania spheres via controlled silver diffusion in Ag–TiO₂ core–shell nanostructures

• Bartosz Bartosewicz,
• Malwina Liszewska,
• Bogusław Budner,
• Marta Michalska-Domańska,
• Krzysztof Kopczyński and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2020, 11, 141–146, doi:10.3762/bjnano.11.12

• investigated using SEM and X-ray photoelectron spectroscopy, respectively. The optical properties of the synthesized structures were characterized using UV–vis spectroscopy. Ag–TiO2 hollow nanostructures with different optical properties were prepared simply by a change of the annealing time in the last

• silver diffusion in Ag–TiO2 core–shell nanostructures (CSNs). Our approach comprises three simple steps starting from the synthesis of the metallic core, through its coating with titania and finally annealing leading to plasmonic hollow nanostructures with plasmon resonance in a broad spectral range. SEM

• structures are shown in Figure 1 (down left) and in Figure 2A. Interestingly, further thermal modification of these fabricated Ag@TiO2 CSNs yields unexpected results. Annealing of Ag@TiO2 nanostructures in a muffle furnace results in Ag diffusion from the silver core into the titania shell. As a result, the

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• structure. In a DNA hybridization process, the oligonucleotides with complementary base sequences are dissolved in a buffer solution and subjected to annealing, which involves a cycle of heating the solution followed by cooling [31]. Seeman and co-workers envisioned the construction of 3D nanoarchitectures

• compared to ssDNA. The selection of the correct base pairing sequence and order enabled the assembly of DNA with balanced rigidity and flexibility within the nanomaterial systems. The maintenance of an exact stoichiometry and long annealing period were the major criteria to achieve defect-free

• inserted into the center of a 13-mer oligonucleotide sequence in an automated DNA synthesizer through phosphoramidite chemistry. The annealing of porphyrin-tethered oligonucleotides with complementary oligonucleotides resulted in the formation of a B-form DNA duplex. The conformational distortion effect

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• the geometry from faceted to more rounded shapes were observed with increasing annealing temperature. Kinetic Monte Carlo simulations indicate that the NPs become rounded due to the minimization of the surface area and the transition to lower energy surface types {111} and {100}. The NPs were

• manipulated on a silica substrate with an atomic force microscope (AFM) in tapping mode. Initially, the NPs were immovable by AFM energy dissipation. However, annealed NPs became movable, and less energy was required to displace the NPs annealed at higher temperature. However, after annealing at 800 °C, the

• particles became immovable again. This effect was attributed to the diffusion of Au into the Si substrate and to the growth of the SiO2 layer. Keywords: annealing; atomic force microscopy (AFM); Au nanoparticles; manipulation; melting; nanotribology; Introduction Gold is one of the most prominent

Recent progress in perovskite solar cells: the perovskite layer

• Xianfeng Dai,
• Ke Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

• -quality perovskite films based on these techniques, researchers control the perovskite morphology by optimizing the solvents for processing [26], varying the annealing temperature [27], adjusting the processing additives [28], sophisticated engineering of the solvent [12][14] and annealing of the solvent

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• . Annealing graphene oxide (GO) in an ammonia atmosphere at 550 °C led to pyridinic N-doped graphene, while at a temperature of 850 °C graphitic nitrogen coexisted with pyridinic nitrogen, and for higher temperatures the amount of graphitic N increased. Annealing GO at 850 °C in the presence of polyaniline or

• -carbonized carbon spheres and stirred for 24 h, followed by refluxing for 5 h at 100 °C and subsequent filtration and drying. Catalytic graphitization was carried out by annealing at different temperatures, between 550 and 1000 °C with steps of 150 °C, in argon atmosphere for 4 h (heating rate 5 °C·min−1

Antimony deposition onto Au(111) and insertion of Mg

• Lingxing Zan,
• Da Xing,
• Abdelaziz Ali Abd-El-Latif and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2019, 10, 2541–2552, doi:10.3762/bjnano.10.245

• paper, we will study the kinetics of the insertion process in more detail [19]. Experimental Chemicals, materials and electrolyte The Au(111) single crystal was prepared by cooling down after flame annealing in pure argon (Air Liquid, 99.999%,) atmosphere as described elsewhere [20]. A typical cyclic

Synthesis and acetone sensing properties of ZnFe₂O₄/rGO gas sensors

• Kaidi Wu,
• Yifan Luo,
• Ying Li and
• Chao Zhang

Beilstein J. Nanotechnol. 2019, 10, 2516–2526, doi:10.3762/bjnano.10.242

• of ZnFe2O4 and reduced graphene oxide (rGO) with different rGO content were prepared via a simple solvothermal method followed by a high-temperature annealing process in an inert atmosphere. The X-ray diffraction analysis confirmed that the introduction of rGO had no effect on the spinel structure of

Semitransparent Sb₂S₃ thin film solar cells by ultrasonic spray pyrolysis for use in solar windows

• Jako S. Eensalu,
• Atanas Katerski,
• Erki Kärber,
• Lothar Weinhardt,
• Monika Blum,
• Clemens Heske,
• Wanli Yang,
• Ilona Oja Acik and
• Malle Krunks

Beilstein J. Nanotechnol. 2019, 10, 2396–2409, doi:10.3762/bjnano.10.230

• imposing limitations on the substrate size [43][44]. A recent paper showed a PCE of 4.6% in solar cells based on Sb2(S,Se)3 grown onto planar CdS by USP, followed by Se vapor annealing at ≈400 °C. However, pristine Sb2S3 solar cells consistently yielded a PCE below 0.1% [45]. This clearly illustrates the

• demonstrated that by adapting a two-step sequence, whereby amorphous Sb2S3 layers are first deposited by USP and then crystallized by thermal annealing, compact Sb2S3 thin films with uniform thickness can be fabricated [46]. Similarly, a two-step procedure to grow compact Sb2S3 thin films has become common

• pattern of the vacuum-annealed sample matched orthorhombic Sb2S3 (ICDD PDF 01-075-4012). The Raman spectrum of the as-deposited Sb2S3 layer contains two broad bands (Figure 1e), which are characteristic of amorphous Sb2S3 [28][46]. After vacuum annealing, characteristic narrower bands of Sb2S3 are

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• defects. The maximum H+ concentration was simulated to be at 2 µm under the sample surface. Annealing at different temperatures under neutral N2 atmosphere was used to promote the presence of different defects (VSi without annealing, 750 °C for 30 min for VSiVC, 900 °C for 30 min for NCVSi). The following

• -temperature PL shows an enhancement by a factor of up to 5.5 for VSi in sample 1 and by a factor of 2.3 for VSiVC in sample 3. Our results also confirm the conversion of VSi to VSiVC during annealing [55] from sample 2 to sample 3. The enhancement of VSi in sample 2 appears to be lower than that in sample 1

• after the fabrication of the pillars. For excitation at 940 nm the PL spectra of sample 3 shows the activation of the NCVSi emission at low temperature [35] after annealing at a higher temperature (Figure 3). Only sample 3 at 940 nm excitation is shown here, as it is most exemplary for the formation of

Polyvinylpyrrolidone as additive for perovskite solar cells with water and isopropanol as solvents

• Chen Du,
• Shuo Wang,
• Xu Miao,
• Wenhai Sun,
• Yu Zhu,
• Chengyan Wang and
• Ruixin Ma

Beilstein J. Nanotechnol. 2019, 10, 2374–2382, doi:10.3762/bjnano.10.228

• for 10 min. Then the film was submerged in the MAX solution (the concentration of the MAX solution was 40 mg/mL MAI and 10 mg/mL MACl) for 500 s to prepare the CH3NH3PbI3 layer, and the films were dried by spinning at 3000 rpm for 10 s and annealing at 120 °C for 10 min. Subsequently, the hole

• irradiated by UV/ozone. The following most critical point in the production of the perovskite layer was to spin the lead nitrate onto the SnO2 ETL. Then, the layer was introduced into a bath of MAX solution for 500 s, and finally dried by spinning and annealing at 120 °C for a period of 10 min. The SEM

Design and facile synthesis of defect-rich C-MoS₂/rGO nanosheets for enhanced lithium–sulfur battery performance

• Chengxiang Tian,
• Juwei Wu,
• Zheng Ma,
• Bo Li,
• Pengcheng Li,
• Xiaotao Zu and
• Xia Xiang

Beilstein J. Nanotechnol. 2019, 10, 2251–2260, doi:10.3762/bjnano.10.217

• improved through the combination of amorphous carbon and rGO, which could also limit the dissolution of polysulfides. After annealing at different temperatures, it is found that the C-MoS2/rGO-6-S composite annealed at 600 °C yields a noticeably enhanced performance of lithium–sulfur batteries, with a high

• specific capacity of 572 mAh·g−1 at 0.2C after 550 cycles, and 551 mAh·g−1 even at 2C, much better than that of MoS2-S nanosheets (249 mAh·g−1 and 149 mAh·g−1) and C-MoS2/rGO-S composites (334 mAh·g−1 and 382 mAh·g−1). Our intended electrode design protocol and annealing process may pave the way for the

• construction of other high-performance metal disulfide electrodes for electrochemical energy storage. Keywords: annealing; double modification; high-performance electrodes; lithium–sulfur battery; molybdenum disulfide (MoS2); reduced graphene oxide (rGO); Introduction Lithium–sulfur (Li–S) batteries have

Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC₇₁BM-based organic photovoltaic cells

• Olivia Amargós-Reyes,
• José-Luis Maldonado,
• Omar Martínez-Alvarez,
• María-Elena Nicho,
• José Santos-Cruz,
• Juan Nicasio-Collazo,
• Irving Caballero-Quintana and
• Concepción Arenas-Arrocena

Beilstein J. Nanotechnol. 2019, 10, 2238–2250, doi:10.3762/bjnano.10.216

• atmospheric conditions [30][32][33][34]. The performance of the OPVs depends on the misalignment of the energy levels of each component, as well as on the organic compounds and the architecture used, on the type of solvents, the deposition technique of the active layer, the annealing conditions and the

• were spin-coated onto ITO/PEDOT:PSS at 1900 rpm for 60 s at atmospheric conditions, and then the films were annealed at 80 °C for 15 min (active layer thickness ≈100 nm). A PFN layer (≈5–10 nm) was spin-coated at 6000 rpm on top of the active layer and exposed to thermal annealing for 15 min at 80 °C

Facile synthesis of carbon nanotube-supported NiO//Fe₂O₃ for all-solid-state supercapacitors

• Shengming Zhang,
• Xuhui Wang,
• Yan Li,
• Xuemei Mu,
• Yaxiong Zhang,
• Jingwei Du,
• Guo Liu,
• Xiaohui Hua,
• Yingzhuo Sheng,
• Erqing Xie and
• Zhenxing Zhang

Beilstein J. Nanotechnol. 2019, 10, 1923–1932, doi:10.3762/bjnano.10.188

• both XRD pattern and Raman spectra indicate that Fe2O3 is not well crystallized since it was formed at 70 °C in the drying oven without further annealing. The XPS spectrum in Figure S5a (Supporting Information File 1) shows the existence of Fe, O, and C elements in CC-CNT@Fe2O3. The Fe 2p spectrum

Fabrication and characterization of Si_1−xGe_x nanocrystals in as-grown and annealed structures: a comparative study

• Muhammad Taha Sultan,
• Adrian Valentin Maraloiu,
• Ionel Stavarache,
• Jón Tómas Gudmundsson,
• Andrei Manolescu,
• Valentin Serban Teodorescu,
• Magdalena Lidia Ciurea and
• Halldór Gudfinnur Svavarsson

Beilstein J. Nanotechnol. 2019, 10, 1873–1882, doi:10.3762/bjnano.10.182

• impulse magnetron sputtering (HiPIMS). The as-grown structures subsequently underwent rapid thermal annealing (550–900 °C for 1 min) in N2 ambient atmosphere. The structures were investigated using X-ray diffraction, high-resolution transmission electron microscopy together with spectral photocurrent

• annealing results in the periodically arranged columnar self-assembly of SiGe core–shell nanocrystals. An increase in photocurrent intensity by more than an order of magnitude was achieved by annealing. Furthermore, a detailed discussion is provided on strain development within the structures, the

• obtain NCs embedded in an oxide matrix is by thermal annealing of multilayer structures. Several oxide matrices have been studied already [12][13][14][15][16][17][18], of which SiO2 is the most extensively studied as it remains amorphous up to high temperatures and due to its compatibility with Si-based