Fabrication of nanoporous silicon by ion implantation

© Springer Science+Business Media Dordrecht 2015. Ion implantation is an advanced new technological method for the fabrication of nanoporous silicon material with metal nanoparticles. The methodology of this technique is developed by Ag+-ion implantation with an energy of 30 keV and a dose of 1.5·1017ion/cm2into a polished monocrystalline silicon substrate. By using Raman spectroscopy, SEM and AFM measurements it is found that amorphous layers of porous silicon (PSi) with an average size of the porous holes on the order of 150–180 nm, a depth of about 100 nm and a wall thickness of about 30–60 nm are formed on the Si surface as a result of ion irradiation. Ion implantation is also applied to locally modify the surface of Si to create periodic plasmonic PSi microstructures with Ag nanoparticles with a diameter of 5–10 nm. The results obtained clearly demonstrate how low-energy ions can be used for the fabrication of photonic microstructures on Si surfaces in a single-step process, similarly as it was recently done for Cu+-ion implanted silica glass

Effects of Gamma-Irradiation and Ion Implantation in Chalcogenide Glasses

© 2016 Elsevier Inc. All rights reserved.A review of recent results on the structural modification of binary and ternary chalcogenide glasses (ChGs) after 60Co γ-irradiation with energy of 1.25MeV and accumulated doses in the range of 0.76-7.72MGy and Cu+-ion implantation with energy of 40keV and radiation dose of 1.5×1017 ion/cm2 at ion-beam current density of 1μA/cm2 is presented. New insight into the radiation-stimulated processes in the γ-irradiated ChGs is reported. In particular, it is shown that the defect structure of As2S3 and Ge15.8As21S63.2 alloys in the radiation-modified state is different, obviously, as a result of various mechanisms of radiation-induced defect formation. The synthesized Cu nanoparticles in As2S3 and Ge15.8As21S63.2 glasses are experimentally confirmed. The nonlinear optical properties studied for the ion-implanted samples demonstrate an existence of simultaneously saturated nonlinear absorption and two-photon nonlinear absorption, the latter being dominated with increasing of laser power

Nanoindentation test of radiation-modified As<inf>2</inf>S<inf>3</inf> glass after ⁶⁰Co gamma-irradiation

© 2016, Editorial Department of Journal of the Chinese Ceramic Society. All right reserved.The results of the surface mechanical properties (i.e., hardness and elastic modulus) in the unmodified and radiation-modified As2S3 glass measured about 10 years after 60Co γ-irradiation, using a nanoindentation test with an ultra nano hardness tester (UNHT) were reported. It is indicated that the γ-irradiated g-As2S3 (g- for glassy) with the average energy of 60Co γ-quanta of 1.25 MeV and the accumulated dose of 2.41 MGy exhibits the increased surface hardness and elastic modulus values, compared to the unirradiated material, in the range of 200-1 600 nm indentation depth. In the long-term radiation-induced improvement of the surface mechanical properties in g-As2S3, the broader distribution of the experimental data was detected for the irradiated sample with radiation-induced oxidized layer, compared to the clean sample without the layer that was removed by washing and polishing

On the application of methods of positron annihilation spectroscopy for studying radiation-stimulated processes in chalcogenide glassy semiconductors

Unirradiated and γ-irradiated (average energy E = 1.25 MeV and dose Φ = 2.41 MGy) chalcogenide glassy semiconductors (CGSs) As2S3 and Ge15.8As21S63.2 are studied by positron annihilation lifetime spectroscopy (PALS) and Doppler broadening of the 0.511-MeV annihilation line (DBAL). Two 22Na positron sources with activities of 0.6 and 2.0 MBq and Kapton film thicknesses of 8.0 and 25.0 μm, respectively, are used. It is shown that radiation-induced changes in the PALS parameters of the CGS types under study are within measurement errors. The DBAL method appeared more efficient and accurate for studying radiation-stimulated processes in CGSs. © 2014 Pleiades Publishing, Ltd

Optical characterization of nanocomposite polymer formed by ion implantation of boron

© 2017, Springer Science+Business Media New York.The boron-ion-implanted polymethylmethacrylate (B:PMMA) samples formed with an energy of 40 keV, ion doses ranging from 6.25 × 1014 to 2.5 × 1016 B+/cm2, and current density of 1016 B+/cm2) in the course of ion-induced carbonization are observed. The value of optical band gap energy of boron-ion-implanted layer Egopt,B was estimated given thickness of implanted layer as a maximum penetration depth of B+ ions into PMMA by slow positron beam spectroscopy in agreement with SRIM simulation results. On the basis of Egopt,B values, a number of carbon atoms in carbonaceous clusters N for the B:PMMA was calculated. It is found the existence of three regions of ion doses (1) 6.25 × 1014 ÷ 3.13 × 1015 B+/cm2, (2) 3.75 × 1015 ÷ 6.25 × 1015 B+/cm2, and (3) 1.25 × 1016 ÷ 2.5 × 1016 B+/cm2, showing thresholds in the estimated Egopt,B and N values as a function of ion dose for the B:PMMA studied. The ion-induced structural evolution towards formation of carbon nanostructures within these thresholds is suggested as explanation of experimental results, taking into account the possible carbonization in high-dose B:PMMA nanocomposite films

Catalytic and biological sensitivity of TiO2 and SiO2 matrices with silver nanoparticles created by ion implantation: A review

The ion implantation of oxide materials such as TiO2 and SiO2 to form silver nanoparticles for catalyst and antibacterial applications is observed. For these purposes the implantation was used at high ion doses that is essential for silver nanoparticle nucleation and grow. It is considered how implanted silver nanoparticles can modify various oxide materials in dependence of irradiation conditions such as ion dose, energy, current density and so on. Some examples of various chemical catalytic and antibacterial reactions in samples with nanoparticles Ag:TiO2 and Ag:SiO 2 are also presented and discussed. It is demonstrated that ion implantation is one of effective perspective modern techniques for fabrication catalyst and biology-active materialists with silver nanoparticles. © 2013 Advanced Study Center Co. Ltd

Structural modification of chalcogenide glasses by gamma-irradiation studied with DBAL technique

The original experimental results on the study of structural modification of chalcogenide glasses by 60Co γ-irradiation with energy of 1.25 MeV and dose of 2.41 MGy for As2S3, Ge15.8As21S63.2, Ge9.5As28.6S61.9 and Ge23.5As11.8S64.7alloys using Doppler broadening of annihilation line (DBAL) technique are reported. The γ-irradiation-induced effect is analyzed in terms of Doppler S and W annihilation parameters. In particular, the observed different slope of S -W plots for glassy (g-) As2S3 and g-Ge15.8As21S63.2studied in the unirradiated and γ-irradiated states indicates that the defect structure of these alloys in the radiation-modified state is different, obviously, as a result of various mechanisms of radiation-induced defect formation. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

The influence of low dose ion-irradiation on the mechanical properties of PMMA probed by nanoindentation

© Springer Science+Business Media Dordrecht 2015. The results of investigations of the influence of low dose B+-ion-irradiation (6.25×1014 ion/cm2) on the mechanical properties (hardness and elastic modulus) of polymethylmethacrylate (PMMA) using the nanoindentation tests with an ultra nano hardness tester are reported for the first time. It is established that the dependences of hardness and elastic modulus on the maximum indentation depth show major differences between pristine and ion-implanted samples in the range up to about 400 nm which is consistent with the maximum penetration depth of B+-ions into the PMMA matrix determined earlier by slow positron beam spectroscopy and SRIM simulation (stopping and range of ions in matter)

The influence of low dose ion-irradiation on the mechanical properties of PMMA probed by nanoindentation

© Springer Science+Business Media Dordrecht 2015. The results of investigations of the influence of low dose B+-ion-irradiation (6.25 ´ 1014 ion/cm2) on the mechanical properties (hardness and elastic modulus) of polymethylmethacrylate (PMMA) using the nanoindentation tests with an ultra nano hardness tester are reported for the first time. It is established that the dependences of hardness and elastic modulus on the maximum indentation depth show major differences between pristine and ion-implanted samples in the range up to about 400 nm which is consistent with the maximum penetration depth of B+-ions into the PMMA matrix determined earlier by slow positron beam spectroscopy and SRIM simulation (stopping and range of ions in matter)

Optical properties of chalcogenide glasses with ion-synthesized copper nanoparticles

Substrates of chalcogenide glassy semiconductors As2S3 and Ge15. 8As21S63. 2 are implanted with Cu+ ions (energy 40 keV, radiation dose 1. 5 × 1017 ion/cm2, fixed current density in the ion beam 1 μA/cm2). The composite layers are analyzed by measuring linear optical transmittance and recording nonlinear optical absorption using the Z-scan technique at 780 nm (probe laser radiation with 150-fs pulses; intensity of 25-100 mW). It is ascertained for the irradiated materials that (1) the linear transmission characteristic of the optical surface plasmon resonance (SPR) band, which indicates the formation of copper nanoparticles in the near-surface region, has emerged and (2) there are simultaneously saturated and two-photon nonlinear absorption types; the latter prevails as the intensity of laser irradiation is increased. © 2013 Pleiades Publishing, Ltd