Si single crystal was sequentially implanted with high doses (2∙1016 cm-2) of In+ and Sb+ ions with an energy of 30 keV in order to synthesize a layer of narrow-gap indium antimonide (InSb) in its near-surface region. Implanted Si:(In + Sb) layers in the liquid phase were annealed with a powerful pulsed ( 100 ns) ion beam (C+/H+) with an energy of 300 keV and a pulse-energy density of 1.0 J/cm2. Calculation of the total depth profile of the concentration of implanted In and Sb atoms taking into account ion sputtering showed their maximum concentration of 40 at.

The visible room-temperature emission and excitation photoluminescence spectra were studied as a function of the indium and arsenic profiles in the In+ and As+ ion-implanted thermally grown SiO2 films before and after the annealing at the temperature of 900 degree celsius. As+ ions at the energy of 40 or 135 keV and In+ ions at the energy of 50 keV, providing a projective range ratio R-p(As)/R-p(In) of 1 or 3, respectively, were used. Four emission photoluminescence bands, peaked at similar to 347 nm (3.57 eV), similar to 440 nm (2.81 eV),similar to 450 nm (2.75 eV) and similar to 500 nm (2.48 eV), were obtained from the 40 keV As+ and 50 keV In+ ion-implanted samples under the excitation wavelength of 300 nm (4.13 eV), 350 nm (3.54 eV), 400 nm (3.10 eV) and 450 nm (2.75 eV), respectively. As the As+ energy increased to 135 keV, under the same excitation conditions, the emission bands peaked at 370 nm (3.35 eV), 420 nm (2.95 eV), 460 nm (2.69 eV) and 505 nm (2.45 eV) dominated in the photoluminescence spectra. The excitation spectra of the observed emission peaks were studied, too. We preliminarily interpret the observed photoluminescence peaks as a result of the T-1 -> S-0 transition of molecular-like clusters associated with the oxygen deficiency provided by In or In-As in ion-implanted SiO2.

Silicon’s band gap ($\mathbf{1 . 1 2} \mathbf{~ e V}$) limits its near-infrared photon absorption. Silicon hyperdoping creates energy states within the band gap, enabling near-infrared radiation absorption. Ion implantation is an efficient method for hyperdoping, but radiation-induced defects compromise silicon crystallinity. Pulsed laser annealing mitigates induced defects, enhancing material crystallinity. The study investigates the impact of pulsed laser annealing on sulfur hyperdoped silicon properties prepared by ion implantation.

GaN films epitaxially grown on sapphire substrates and stored for more than a year under normal conditions were treated using pulsed mixed carbon-hydrogen ion beam. The electronic structure transformations of GaN on sapphire samples were studied using X-ray photoelectron spectroscopy (XPS), optical absorption, photoluminescence and density functional theory (DFT)-based simulations after such treatment. Weak acidification in the form of Ga-N...O was revealed by XPS method for both as-grown and ion-irradiated GaN on sapphire samples. GaN decomposition and Ga-loss effects were not detected after pulsed ion-beam treatment (PIBT), either experimentally or theoretically. It was shown that PIBT promotes a narrowing of the bandgap, changes the vacancy concentration in the surface region, and provides hydrogenation of the surface with the formation of hydroxyl groups in nondefective areas of the surface and near surface layers. PIBT-induced densification of the layers is observed due to annealing of vacancies; no detectable changes in the surface area morphology were found. The weak shift of the valence band edge corresponds to the contribution from areas with more nitrogen defects. The presence of these states in the bandgap could be the possible source of an increase in the electro and photocatalytic activity of GaN epitaxial films.

A study of the electrical and photoelectric properties of the heterostructure of barium strontium titanate film on a silicon substrate was performed. The conductivity of the heterostructure significantly increased and the capacitance decreased with frequency. The photoconductivity significantly increased for the sample modified by Cr+ ion implantation. The temperature dependence of the resistance under green laser irradiation demonstrated maxima at 150 K.

В данной работе проведено формирование гипердопированных слоев Si с примесями халькогенов (Se, Te), металлов (Fe, Cr), а также слоев Si с наночастицами узкозонного материала InSb. Образцы были получены при имплантации монокристалла p-Si(111) ионами Se+ , Te+ , Fe+ , Cr+ , а также при последовательной имплантации ионами Sb+ и In+ . После имплантации проводился отжиг аморфизованных слоев Si импульсами рубинового лазера ( = 0.694 мкм, 80 нс) или мощным пучком ионов углерода и водорода (C + , H+ , 300 кэВ, 100 нс) на ускорителе ТЕМП в жидкофазном режиме через процессы плавления и кристаллизации. Указанные процессы при лазерном отжиге диагностировались in-situ методикой регистрации отражения R(t) в облучаемой лазером зоне, позволяющей определить время жизни расплава. Оптические свойства полученных слоев исследовались на пропускание T и отражение R в области длин волн 0.5-10 мкм для определения их поглощательной способности (A=1- R-T).

A study of the optical, electrical, and photoelectric properties of the heterostructure of barium strontium titanate film on a silicon substrate was performed. An intense maximum is observed in the absorption spectrum of the heterostructure at 410 nm. The conductivity of the heterostructure significantly increases and the capacitance drops with increasing frequency. Photostimulated conductivity measurement showed that the intensity of photoconductivity significantly increased for the sample modified by Cr(+)ion implantation. The temperature dependence of the resistance under UV and green laser irradiation showed maxima at 100 and 150 K, and then the resistance decreased with increasing temperature.

We studied the luminescence and the thermal stability of defects formed in α-Al2O3 single crystals after pulsed treatment with a beam of C+/H+ ions with an energy of 300 keV and a pulse duration of ~80 ns. By measuring optical absorption, photoluminescence, and pulsed cathodoluminescence, it is found that this type of exposure leads to intense generation of both single F and F+ centers and more complex defects (F2 aggregate centers or vacancy–impurity complexes) in α-Al2O3. The thermal stability of F-type defects formed in α-Al2O3 upon exposure to a pulsed ion beam is comparable to the stability of radiation-induced defects in neutron-irradiated samples.

Luminescence and thermal stability of defects formed in alpha-Al2O3 single crystals under pulsed ion beam treatment (C+/H+ ions with an energy 300 keV, pulse duration 80 ns) were investigated. This type of irradiation leads to the intensive generation of both single F- and F+-centers and more complex defects (F2-type aggregate centers or vacancy-impurity complexes) in alpha-Al2O3. It was confirmed by the results of optical absorption, photoluminescence, and pulsed cathodoluminescence measurements. The thermal stability of F-type defects formed in alpha-Al2O3 under the pulsed ion beam treatment is comparable to the stability of radiation-induced defects in neutron-irradiated samples.

The results of intense pulsed ion beam (IPIB) treatment of the soft magnetic amorphous alloy of a FINEMET-type are presented. Foil produced from the alloy was irradiated with short (about 100 ns) pulses of carbon ions and protons with energy of up to 300 keV and an energy density of up to 7 J/cm 2 . X-ray diffraction, Mössbauer spectroscopy and magnetic measurements were used to investigate structural and magnetic properties of irradiated foils. It is shown that the foil remains intact after the treatment, and the crystal structure still amorphous. Spontaneous magnetization vector is found to lie almost along perpendicular to the foil plane after irradiation, whereas for the initial amorphous foil it belongs to the plane. The magnetic properties of the foil undergo changes: the coercive force decreases, the saturation induction increases slightly, and the magnetization curve has shallower slope.

The luminescence and thermal stability of defects formed in alpha-Al2O3 single crystals after powerful (300 keV) pulsed irradiation with C+/H+ ion beam were investigated. It was found by measuring of optical density, photoluminescence, and pulsed cathodoluminescence that ion irradiation induces both single F-, F+-centers and F-2-type aggregate centers. An intense thermoluminescence band with a complex shape was observed in the broad temperature range of 350-700 K, its intensity decreases with increasing of the energy density of the ion beam. The thermal stability of the F-type defects produced in alpha-Al2O3 after irradiation with a pulsed ion beam is comparable to that in neutron-irradiated samples. The appropriate kinetics of annealing of radiation-induced defects has been analyzed in terms of the diffusion-controlled bimolecular reactions between F-type centers and complementary interstitial oxygen ions. Thus, two important kinetic parameters the migration energy of mobile interstitials and pre-exponential - have been evaluated and discussed.

The paper presents the results of Si surface modification created by implantation with Ag+ ions at energy of 30 key, current density of 8 mu A/cm(2) for various doses from 6.0 center dot 10(15) to 7.5 center dot 10(16) ion/cm(2) and annealed by powerful beam pulses (C+, H+) of nanosecond duration. Scanning electron microscopy and optical reflection measurements showed that after ion implantation an amorphous a-Si layer on the surface of c-Si substrates with Ag nanoparticles was formed. Followed pulse ion beam annealing of sample obtained at lowest dose of 6.0 center dot 10(15) ion/cm(2) leads to melting and recrystallization of the Si surface layer with segregation of Ag nanoparticles. For samples implanted with doses higher than 2.5 center dot 10(16) ion/cm(2) after annealing an epitaxial cellular breakdown structures are fabricated on the Si surface decorated at the cell boundaries by Ag nanoparticles.

AbstractStructural and photoelectric properties of composite Ag:Si layers formed in the near-surface area of a single-crystal c-Si substrate by a high-dose implantation of Ag^+ ions with subsequent pulsed laser annealing (PLA) have been studied. It has been established that, as a result of ion implantation, a maximal concentration of Ag impurity ( N _Ag ~ 4 × 10^22 at/cm^3) is concentrated near the surface and drops to a level of ~10^19 at/cm^3 at a depth of ~60 nm. Meanwhile, Ag nanoparticles and silver oxide (Ag_2O) inclusions are contained in a formed thin layer of amorphized Si (a-Si). Melting of a near-surface area and diffusion redistribution of the implanted impurity have been achieved in conditions of PLA, which increases Ag concentration near the surface and at a depth of 60 nm. Dark current–voltage characteristics of a junction between a Ag:Si layer and a p -Si substrate showed formation of a diode structure as a result of PLA. Photoconductivity measurements on formed samples demonstrate the presence of a photoresponse (photo-EMF) in the range of wavelengths of 500–1200 nm, which intensity increased for samples that are subjected to PLA when increasing energy density in the pulse. The obtained results demonstrate the potential use of composite Ag:Si layers and the method of their formation in the technology of photodetectors.

The doping of near-surface region of single crystalline p-type Si by Fe impurity under irradiation by the low-energy and high-current Xe+ ion beam is investigated. The recoil-atom implantation method was applied which utilizes simultaneous sputtering of Fe target with irradiation of the deposited Fe atoms on the Si substrate surface by Xe+ ion beam. The resulting incorporation of Fe atoms into Si leads to formation of very thin (similar to 5 nm) highly doped (>10(22) at/cm(3)) surface layer (Si:Fe) containing Si and alpha-Fe nanoparticles with sizes of 5-20 nm. Such a layer demonstrates ferromagnetism at T = 10 K and superparamagnetism at 300 K. Inversion of the conductivity type (from p-to n-type) in the heavily doped Si:Fe layer and formation of n-p junction to the substrate is observed. A photoresponse of thus obtained n-Si:Fe/p-Si diode structure demonstrates an intense signal in the wavelength range of 500-1200 nm with a maximum at about 950 nm under the low reverse bias voltage (U =1 V), whose integral intensity is comparable with that for commercial silicon photodiode at U = 10 V.

Ge layers heavily doped by a donor impurity are formed by implanting a p-Ge single crystal by two-charge antimony ions (Sb++) with the energy E = 80 keV and the dose Φ = 1016 cm−2 with subsequent pulsed annealing of the implanted Ge:Sb layer by powerful ion beams (C+, H+) of nanosecond duration in a liquid phase regime. The surface morphology and depth profiles of Sb, the crystalline structure of the layer, the concentration of electrically active atoms, and photoluminescence of the Ge:Sb layers are investigated. The data on the Sb depth distribution are compared with the computer simulation results and show good agreement. The obtained results indicate that a high degree of activation of the implanted Sb (up to 100%) and an increase in the direct-gap photoluminescence in the heavily doped layer for 300 K with a peak at 0.77 eV.