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The 23^rd Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics (RYCPS) was held in Saint Petersburg on November 23 – 26, 2021. It was organized by Peter the Great St. Petersburg Polytechnic University.

The program of the Conference included semiconductor technology, heterostructures with quantum wells and quantum dots, bulk properties of semiconductors, opto- and nanoelectronic devices and new materials. Given the restrictions on meetings of a large number of people associated with COVID-19, the organizing committee of the conference decided to hold it in a virtual format. The oral sessions were held on the Zoom platform, and the poster session was organized using the Miro online whiteboard and the Skype platform. This provided an opportunity for valuable discussions between the conference participants and experienced scientists.

The conference included two invited talks given by leading scientists from Ioffe Institute, devoted to actual problems and major advances in physics and technology. The keynote speakers were Anton Vershovskii (presentation "Optical quantum sensors based on thermal atoms and atom-like structures") and Mikhail Glazov (presentation "Spin noise in semiconductors"). Students, graduate and postgraduate students presented their results on plenary and poster sessions. The total number of accepted abstracts published in Russian (the official conference language) was 105. Here we publish 24 selected papers in English.

Like previous years, the participants were involved in the competition for the best report. Certificates and cash prizes were awarded to a number of participants for the presentations selected by the Program Committee. Alexey Kuznetsov (Alferov University, Saint Petersburg) was awarded for the best presentation among students with a report "Influence of plasmonic effects on the localization of electromagnetic waves in GaP nanowires". Sergey Savchenko (Ural Federal University, Yekaterinburg) was awarded for the best presentation among postgraduate students with a report "Thermal quenching of luminescence of excitons and defect centers in InP/ZnS quantum dots". Works with potential applications were recommended for participation in the following competition for support from the Russian Foundation for Assistance to Small Innovative Enterprises in Science and Technology.

List of Editors, Organizers, Sponsors, Program Committee, Organizing Committee are available in this pdf.

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

• Type of peer review: Single Anonymous

• Conference submission management system: Morressier

• Number of submissions received: 54

• Number of submissions sent for review: 25

• Number of submissions accepted: 24

• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 44.4

• Average number of reviews per paper: 2

• Total number of reviewers involved: 19

• Contact person for queries:

Name: Prof. Vadim Shalygin

Email: shalygin@rphf.spbstu.ru

Affiliation: Peter the Great St Petersburg Polytechnic University - Institute of Electronics and Telecommunications

Graphitization of the (111) face of diamond irradiated with fast neutrons under single pulses of the third harmonic of a Ti: sapphire laser (100 fs, 266 nm) is investigated. Transformations of the structure of the graphitized material along the surface of laser spots formed by the pulses at different energies are investigated by confocal Raman spectroscopy. It is found that irradiation of diamond with fast neutrons lowers the graphitization threshold by about five times compared with that of unirradiated diamond.

Two types of natural diamonds were investigated by means of PL scanning and ODMR. One was irradiated by neutrons to create NV-centers and the second wasn't specifically treated. The pattern of NV-center distribution was found such that NV-centers in untreated diamond are localized in a special direction, supposedly sliding planes. Furthermore, the spin Hamiltonian parameters E and D of NV-center ground state, calculated by ODMR spectra in untreated diamond, depend on the surface point.

A new method for the formation of a diluted magnetic semiconductor based on gallium arsenide doped with iron and manganese atoms is considered. The method consists in diffusion doping during pulsed laser deposition in vacuum. Using the method of X-ray photoelectron spectroscopy, the profile of the chemical elements distribution was obtained. The magnetic phases influence on the behavior of the magnetic field dependence of the Hall resistance is analyzed. The technological parameters for the growth of the structure exhibiting ferromagnetic properties at room temperature were selected.

In this work, the process of phosphorus desorption from epi-ready InP(001) substrates during high-temperature annealing in an arsenic flux was experimentally investigated. An InPAs solid solution and InAs islands were formed on the surface upon annealing. The composition of the solid solution, the surface area fraction occupied by InAs islands, and its height depend on the annealing temperature. The phosphorus desorption rate was determined from the dependence of the arsenic atoms number on the substrate surface on the annealing temperature and the holding time in the arsenic flux. The phosphorus desorption rate increased from 6.03×10¹⁰ s⁻¹⋅ cm⁻² at an annealing temperature of 500 °C to 4.38×10¹¹ s⁻¹ ⋅ cm⁻² at 540 °C. The activation energy of the phosphorus desorption process was 2.7 ± 0.2 eV.

The work is concerned with the efficiency of inclusion of the additional layer of por-Si applied as a buffer into the growth technology of AlxGa1-xN/AlN/Si as well as its influence on the morphological parameters and composition of surface of the grown heterostructures. In the course of the study, it was found that the heterostructure grown using a nanoporous por-Si buffer layer on a Si(111) n-type monocrystalline silicon wafer has a more homogeneous structure of the epitaxial layer and its surface morphology.

Here we report on the studies of the controllable synthesis of large area boron nitride films by the resistive heating method on a metal substrate without using a dangerous boron and nitrogen containing gases. In our original home-made CVD setup, we used the copper foil as a metal catalytic substrate. With the solid precursor of ammonia borane, the boron nitride films were synthesized under low pressure conditions and at a growth temperature of about 1000°C. We obtained the films with an area of up to 1x1 cm² by varying the synthesis parameters. The quality of boron nitride films was characterized using Raman spectroscopy and X-ray spectroscopy.

In this work we study zinc oxide nanostructures of various geometries synthesized via the hydrothermal technique on Si (111) substrate. We demonstrate capabilities of the growth protocol for control over the morphology of nanostructures varying from nanowires to hexapods. The obtained samples were studied by photoluminescence spectroscopy to demonstrate a very narrow spontaneous emission near 370 nm. Despite cheap and feasible fabrication, the obtained nanostructures possess high crystallinity confirmed by the absence of typical for ZnO wide emission band in the visible region, related with the structure imperfections. This property together with the capabilities of the geometrical control over the nanostructures unveil perspectives of the reported approach for future UV photonic applications.

The interaction between intersecting vicinal and dislocation-induced atomic steps on crystal surfaces is studied experimentally on Au(111) and GaAs(001) and numerically using Monte-Carlo simulation. The interaction between intersecting steps leads to the "anticrossing" phenomenon which consists in the formation of a three-level relief configuration with the upper and lower terraces separated by a nanometer-sized bridge of intermediate height. The anticrossing effect is driven by the effective repulsion of two new combinatory steps bordering the upper and lower terraces. Two types of asymmetry between the combinatory steps are considered. In particular, the reasons for different curvature radii of the upper and lower combinatory steps are discussed, along with the issue of why dislocation-induced steps remain straight under annealing, while vicinal steps obtain clear visible ledges.

This work investigates the luminescence properties of pseudomorphic nanostructures with Ge_1-x-ySi_xSn_y/Si superlattices (SL) grown on silicon substrates by molecular beam epitaxy. It was shown that the addition of Sn (y = 0.07) to the alloy layers within the structures results in a significant shift of the photoluminescence (PL) spectra towards longer wavelengths (2.0-3.5 μm) compared to similar Ge_0.7Si_0.3/Si superlattices. A series of experiments involving etching the structures to different depths have shown that the observed photoluminescence occurs exactly in the Ge_1-x-ySi_xSn_y/Si SL region, with the sublinear nature of the PL power dependence indicating the probable participation of defects in radiative recombination. A significant increase in low-temperature PL was observed with a decrease in the thickness of narrow-gap SL layers from 6 to 2 nm, as well as with an increase in the number of superlattice periods from 10 to 30. The obtained structures exhibit relatively good temperature stability of luminescence, which is preserved up to 160 K. Thus, the current work demonstrates the possibility of creating mid-wave IR emitting epitaxial structures on silicon substrates.

In this work we propose means to determine the dispersion of light in a semiconductor total internal reflection (TIR) planar waveguide featuring dielectric response of excitons from a quantum well (QW). The given theoretical apparatus is then used to reproduce the data experimentally acquired when probing the AlGaAs-based waveguide (with a GaAs QW in its waveguiding layer) with a continuous laser through a coupling grating and then gathering the light transmitted through the waveguiding layer.

The heating of electrons under longitudinal optical phonon scattering in a triangular GaN/AlGaN quantum well was studied theoretically. The energy loss rate of electrons was calculated in consideration of the dynamical screening and the hot phonon effect. The dependence of the electron temperature on the longitudinal electric field was calculated. The integral terahertz emission of hot two-dimensional electrons was simulated. The role of coupled plasmon-phonon mode scattering in the GaN/AlGaN quantum well was discussed.

The results of modeling a finite system of interacting two-dimensional electrons placed at zero temperature into an external parabolic potential well are presented. The structure of the 2D Wigner cluster is found. The distribution functions of interelectron distances and the coordination numbers of internal and external electrons are obtained. The "string-zigzag" transition is analyzed. The low-temperature specific heat of the system is determined. An electronic Wigner crystal on a sphere is also considered.

In this work, the behavior of the luminescence of mesoporous silicon under irradiation with a femtosecond IR laser is shown by the method of multiphoton microscopy. It was demonstrated that, along with the background photoluminescence of porous silicon, bright photoluminescence centers appear on the layer surface, and under certain conditions. Centers with a different, shorter-wavelength emission spectrum also appear.

Currently, new nanostructured materials based on composite metal oxides is of great interest for the development of gas sensors with improved functional characteristics. In this work, zinc oxide nanowires were synthesized by hydrothermal method. Hierarchical ZnO/ZnFe₂O₄ nanostructures were obtained by immersion of zinc oxide layers in ferrous sulphate aqueous solution. The mechanism of zinc ferrite formation during the interaction of zinc oxide with iron sulphate is considered. The crystal structure of ZnO and ZnO/ZnFe₂O₄ were studied by Raman spectroscopy. The sensitivity of ZnO and ZnO/ZnFe₂O₄ nanostructures to isopropyl alcohol vapors was analyzed. It was shown that there is an optimal concentration of ferrous sulphate used to modify zinc oxide nanowires and synthesize ZnO/ZnFe₂O₄ composite nanostructures.

The initial self-catalyze GaAs nanowire (NW) growth stages were studied using Monte Carlo simulation. We analyzed the effect of the mask-film etching rate with liquid gallium for different thicknesses on the initial nanowire formation stages. At a high etching rate NWs do not form on thick mask-films. A high etching rate of a thin film-mask can lead to lateral Ga drop motion over the crystalline substrate surface, which delays the nanowire formation onset. It is shown that, for the NW formation, it is necessary to maintain the correct ratio between the film thickness, etching rate, Ga and As₂ flux intensities.

We study the conditions of suppressed backward scattering in optical oligomers. Optical oligomers are closely packed clusters of nanoparticles which support multiple resonances, allowing to achieve scattering phase rotation by 2π necessary for metalenses. In this paper we consider the simplest oligomer — a dimer, which is irradiated by a normally-incident plane wave with the magnetic field oriented along the dimer axis. Using the dipole approximation, we have derived analytically the generalized Kerker condition for this system. Similarly to a single sphere case, the electric and magnetic dipole have to be of the same amplitude to suppress the backward scattering. However, due to the inter-particle coupling, the full coupled-dipole problem must be solved to find the wavelength of the backscattering suppression. Using the coupled-dipole and coupled-multipole methods, we have found that the Kerker condition wavelength for the considered dimer is red-shifted compared to a single sphere.

We present a photoluminescence study of In(As,P) monolithic nanoinclusions into Si (100) substrates. The structures were grown in openings of the silicon substrates using an original approach based on the metal-organic vapor epitaxy method. The obtained arrays of In(As,P) nanoinclusions into the Si (100) surface were investigated by scanning microphotoluminescence spectroscopy. The obtained results show high crystalline quality of In(As,P) inclusions with broad emission peak in the near-infrared range of wavelengths.

Linear and third-order nonlinear absorption coefficients have been theoretically investigated in a system of vertically coupled cylindrical double quantum dots with the modified Pöschl-Teller potential in the axial direction and parabolic potential in the radial direction. Also, changes in the refractive index in these conditions were obtained. For intraband optical transitions of charge carriers in such system the selection rules have been obtained. The behaviour of the linear, nonlinear and total absorption spectra and changes in the refractive index have been theoretically observed for different lattice temperatures and illustrated by the corresponding graphs for two temperatures.

The high-voltage p⁺–p⁰–i–n⁰–n⁺ structures based on epitaxial gradual GaAs p⁰–i–n⁰ junction grown in hydrogen or argon atmosphere have been studied by capacitance-voltage spectroscopy and deep-level transient spectroscopy, DLTS, before and after neutron irradiation. After neutron irradiation, the broad bands associated with electron emission from the states lying above midgap appear in DLTS spectra of both p⁰–i–n⁰ GaAs structures. It is assumed that the carrier emission mechanism in the neutron-irradiated GaAs is the same as that in amorphous materials.

The resonant activation of resistance switching (RS) of a memristor based on an yttria stabilized zirconia (YSZ) film with embedded Au nanoparticles (NPs) was investigated. The switching was made by triangular pulses with high frequency (HF) sinusoid added. A non-monotonous dependence a ratio of the electric current through the memristor in the low resistive state to the current in the high resistive one on the HF sinusoid frequency was found. The effect was explained by a finite electron tunneling time between the Pt electrode and Au NPs. This conclusion was supported by measuring a dependence of HF memristor capacitance on the probing signal frequency.

The article is devoted to the study of light-emitting heterostructures based on GaP(As,N) dilute nitrides, monolithically grown on silicon substrates by plasma-assisted molecular beam epitaxy. Current-voltage characteristics and electroluminescence spectra of the grown heterostructures are obtained. For the first time, a unique effect is observed in GaP(As,N) dilute nitrides - the appearance of white electroluminescence when a reverse bias is applied. The result was obtained due to the original design of the light-emitting heterostructure and the unique properties of dilute nitride solid solutions.

This paper is devoted to the comparative study of conductive properties of three types of flexible polymer composites consisting of styrene-butadiene rubber (SBR) as a matrix and graphite, graphene or single-walled carbon nanotubes as fillers. The dependences of the resistivity on the mass fraction of different fillers are measured and analyzed within the framework of the statistical percolation theory. The percolation parameters (the values of the percolation threshold and the critical exponent) are calculated for all studied composites. Their variation depending on the filler type is discussed, taking into account a geometric shape of filler particles and the nature of the conduction process in composites in the percolation range. The sensitivity of the resistivity of synthesized composites to axial deformation at different mass fraction of fillers is also investigated. Using graphite or graphene fillers is observed to result in a higher sensitivity compared to the carbon nanotubes filler. The highest value of the gauge factor is observed when using 23 mass.% graphene filler that indicates graphene/SBR composites to be most promising for creating strain sensors.

Photoluminescence temperature quenching of tetraphenylporphyrins thin films on silicon substrates have been investigated. Free-based tetraphenylporphyrin (H₂TPP) and Zinc-tetraphenylporphyrin (ZnTPP) films were obtained by thermal evaporation in vacuum. The photoluminescence properties of these samples are observed in the wide temperature range from 77 to 300 K. The temperature-depended photoluminescence intensity of ZnTPP exhibits abnormal behaviour. An increase in the photoluminescence intensity is observed in the temperature range of 77-180 K. We suppose that charge carriers are trapped by non-radiative centres when the temperature decreases down to 77 K. The release of carriers occurs with a further temperature increase. In addition, there are sharp increases in the luminescence intensity of thin H₂TPP and ZnTPP films at a temperature of 270 K, which are associated with a second-order phase transition.

We demonstrate a new technique to fabricate silver dendritic structures in a subsurface glass layer based on electrolysis of silver-enriched glass. Chemical etching of glass in water diluted HF allows "opening" of the dendrites for their characterization, which makes possible their use for Surface-enhanced Raman scattering. The structure and morphology of the dendrites were characterized using atomic force and scanning electron microscopy, and energy-dispersive X-ray spectroscopy. It was demonstrated that the surface morphology of the formed structures depends on the electric charge passed through the sample during the electrolysis and the duration of the chemical etching. The presented method does not require expensive equipment and materials and allows one to form silver nanostructures of a prescribed pattern.