Simulation of proton channeling through vertically aligned carbon nanotube arrays has been carried out by the molecular dynamics method. The calculation results are compared with the experimental data on the angular distribution of the characteristic X-ray yield obtained from the hydrogen ion irradiation of the carbon nanotube arrays grown on porous Al2O3 membranes.

Статья подготовлена в рамках аналитической ведомственной целевой программы «Развитие научного потенциала высшей школы(2009–2011)», проект №2.1.3/12135: «Древнерусский четий сборник как литературный факт (канон и творческие модификации)».

Features of controlling the wavelength of emission from laser heterostructures with strained InGaAs/GaAs quantum wells by irradiation with medium-energy (with the energy as high as 150 keV) protons are studied. It is established that irradiation with H+ ions and subsequent thermal annealing at a temperature of 700°C make it possible to decrease the wavelength of emission from quantum wells. As the dose of ions is increased from 1013 to 1016 cm−2, the magnitude of change in the wavelength increases to 20 nm. Starting with a dose of 1015 cm−2, a significant decrease in the intensity of emission is observed. The optimum dose of H+ ions (6 × 1014 cm−2) and annealing temperature (700°C) for modifying the InGaAs/GaAs/InGaP laser structures are determined; it is shown that, in this case, one can obtain a shift of ∼(8–10) nm for the wavelength of laser radiation with low losses in intensity with the quality of the surface of laser structures retained. The observed “blue” shift is caused by implantation-stimulated processes of intermixing of the In and Ga atoms at the InGaAs/GaAs interface.

The possibility of controlling the wavelength of emission from an InGaAs/GaAs/InGaP laser heterostructure with strained quantum wells (QWs) using medium-energy proton implantation followed by thermal annealing has been studied. It is established that the optimum proton energy is related to the arrangement of QWs in the structure (e.g., 150 keV for QWs at a depth of ≈1.3 μm). Proton irradiation to a total dose of 6 × 10 14 cm −2 followed by annealing at 700°C allows the wavelength of emission from the modified region to be decreased by 8–10 nm at minimum losses in the output intensity. The observed effect can be used to obtain two-band emission from the same chip and has good prospects for use in the development of new optoelectronic schemes.

The effect of joint phosphorus and boron ion implantation doping by shallow donor and acceptor impurities on the enhancement of porous silicon (PS) photoluminescence (PL) quantum output has been studied in the visible and near-visible IR radiation bands. The impact of ion irradiation and subsequent oxidizing annealing on PL and electron paramagnetic resonance of samples has been investigated before and after PS formation on silicon single crystals heavily arsenicor boron-doped up to the level of ≈1019 cm-3. It has been shown that there exists an optimum joint content of shallow donors and acceptors providing the maximum of PL intensity near the red edge of the visible spectrum. The PL quantum output is estimated 100 times higher as compared to that of PS formed on silicon without ion irradiation.

The influence of P ion doping on the photoluminescence (PL) of the system of nanocrystals in SiO2 matrix (SiO2:Si) both without annealing and after annealing at various temperatures (provided before and after additional P implantation) is investigated. The Si and P implantation was carried out with ion energies of 150keV and doses ΦSi=1017cm−2 and ΦP=(0.1–300)×1014cm−2 (current density j⩽3μAcm−2). The system after Si implantation was formed at 1000°C and 1100°C(2h). For the case of SiO2:Si system as-implanted by P, the intensity of PL was drastically quenched, but partially retained. As for the step-by-step annealing (at progressively increased temperatures) carried out after P implantation, the sign and degree of doping effect change with annealing temperature. The possible mechanisms of these features are discussed.

The electrical properties and structural perfection of high-purity p-type germanium layers implanted with phosphorus ions were studied. The minimum annealing temperature required to activate implanted phosphorus atoms and to produce an n-type layer was evaluated as a function of ion bombardment conditions. The phosphorus activation level was evaluated, and the depth of the p-n junctions was measured as a function of ion energy, implant dose, annealing temperature, and holding time.

Stress-induced DNA breaking may occur partially as a result of decrease in 5-methyl cytosine content. Poststressory activation of transcription was shown to follow the stimulation of the DNA repair synthesis. The processes studied involved two phases and were tissue-dependent.