2304-9782, 2618-8686, 2405-7223 St. Petersburg Polytechnic University Journal: Physics and Mathematics 18 1.1 2025 1-159
CNF RUS 6-10 0009-0002-1428-3323 Berdnikov Vladimir Spin Optics Laboratory, St. Petersburg State University Kavokin Kirill kkavokin@gmail.com
St. Petersburg, Russian Federation
 0000-0003-3836-1250 Kuznetsova Maria Spin Optics Laboratory, St. Petersburg State University Litvyak Valentina valiok.ok@gmail.com
St. Petersburg, Russian Federation
 St. Petersburg State University Bazhin Pavel bazhin2014@yandex.ru Spin-lattice relaxation processes of nuclear spins in GaAs:Mn This paper presents a theoretical investigation of nuclear spin-lattice relaxation time in epitaxial layers of GaAs doped by Mn ions (the concentration of the deep acceptor Mn 3∙1017 cm−3) under optical pumping conditions at the  lattice temperature of 4.5 K. Earlier experiments by the optical orientation method showed that the spin-lattice relaxation time depends on the magnitude of the external magnetic field and reaches up to 20 seconds for this sample.  Such behavior is not typical for p-type semiconductors and is more similar to the nuclear spin system dynamics in n-type GaAs. To determine the reasons for the significant difference in the spin-lattice relaxation time between p-GaAs  and GaAs:Mn, the influence of two possible nuclear spin relaxation mechanisms specific to this material has been evaluated. It is demonstrated that the nuclear spin-lattice relaxation under the action of fluctuating magnetic fields of paramagnetic Mn centers in GaAs does not play a significant role. Relaxation limited by spin diffusion due to hyperfine interaction with Mn holes localized on deep acceptors can make a noticeable contribution to the relaxation rate. 10.18721/JPM.181.101 538.958 semiconductors gallium arsenide nuclear spin spin dynamics spin-lattice relaxation optical orientation https://physmath.spbstu.ru/article/2025.79.1/
CNF RUS 11-16 M.N. Mikheev Institute of Metal Physics; Ural Federal University Fominykh Bogdan fominykh@imp.uran.ru
Ekaterinburg, Russian Federation
 0000-0002-5942-5885 Institute of Metal Physics, Ural Division of the RAS Irkhin Valentin valentin.irkhin@imp.uran.ru M.N. Mikheev Institute of Metal Physics, UB RAS Perevalova Aleksandra domozhirova@imp.uran.ru
Ekaterinburg, Russian Federation
 M.N. Mikheev Institute of Metal Physics, UB RAS Naumov Sergey naumov@imp.uran.ru
Ekaterinburg, Russian Federation
 M.N. Mikheev Institute of Metal Physics; Ural Federal University Marchenkov Vyacheslav
Ekaterinburg, Russian Federation
 Non-ideal experimental Berry phase in the topological insulator Bi2Se3 single crystal Magnetoresistivity and Hall resistivity of a bulk Bi2Se3 single crystal are investigated. It is found that in high magnetic fields (above 7 T), the Shubnikov – de Haas effect is observed. The Berry phase determined using the standard  Lifshitz – Onsager formalism is ФB ≈ 0.8π, which indicates the presence of Dirac fermions in the system. At the same time, ФB deviates from the ideal π value. It is shown that it is important to take into account the Zeeman interaction and the non-ideality of the Dirac dispersion relation for surface states for correct description of topological effects. 10.18721/JPM.181.102 538.9 Berry phase magnetoresistivity Shubnikov – de Haas oscillations Landau level fan diagram Hall effect topological insulator Bi2Se3 https://physmath.spbstu.ru/article/2025.79.2/ 02_11-16_18(1_1)2025.pdf
CNF RUS 17-21 0000-0002-6373-9289 Ioffe Institute Khvostikova Olga olgakhv@mail.ioffe.ru Ioffe Institute Kornienko Polina polina.kornienko.2003@mail.ru 0000-0003-0107-504X Ioffe Institute Khvostikov Vladimir vlkhv@scell.ioffe.ru Ioffe Institute Salii Roman r.saliy@mail.ioffe.ru
St. Petersburg, Russian Federation
 Epitaxial growth AlGaAs from Bi-containing melts Liquid-phase epitaxy from gallium melts is generally associated with difficulties arising in obtaining epitaxial layers of n-type conductivity in the high-temperature growth range, especially using a graphite boat. One of the possibilities for purifying the epitaxial layer from background impurities and reducing the concentration of antistructural defects is using Bi-containing melt solutions. A high initial crystallization temperature is necessary to obtain a thick (50 μm and more) AlGaAs epitaxial layer. Relatively thick graded AlxGa1−xAs layers are used to obtain photovoltaic converters with lateral input of laser radiation, as well as in high-brightness light-emitting diodes. At an initial epitaxy temperature above 850 °C from the liquid phase in a graphite boat, intentionally undoped GaAs and AlGaAs layers change the conductivity type from n- to p-type. This paper shows that adding bismuth to the melt allows preserving the initial n-type conductivity of the grown AlGaAs layers, which simplifies the technological process of creating a photovoltaic device structure with a given doping level of the epitaxial layers. It is shown that the concentration of impurity centers decreases with an increase in the bismuth content in the gallium melt. 10.18721/JPM.181.103 532.78; 629.7.064.56 photovoltaic converter liquid phase epitaxy AlGaAs background impurities https://physmath.spbstu.ru/article/2025.79.3/
CNF RUS 22-27 0000-0002-0358-7818 Yakushova Nadezhda Filippov Ivan ivn.filippov@gmail.com 0000-0001-8318-8149 Karmanov Andrey gubich.niifi@gmail.com Gubich Ivan 0000-0003-3037-3601 Pronin Igor Nanostructured engineering of ZnO:Cu:Al nanomaterials for sensor and photocatalytic applications Nanomaterials based on zinc oxide co-doped with copper and aluminum of varying concentrations were obtained using the sol-gel technology adapted to solve problems of nanostructural engineering. Experimental scanning electron  microscopy data show that varying the concentration of co-dopants allows flexible control of the nanomaterial structure. Optical properties of ZnO:Al:Cu were studied in the visible and ultraviolet radiation ranges. It was found for all  the studied samples that there is an insignificant decrease in radiation transmission compared to unmodified zinc oxide, while they still remain optically transparent. A non-monotonic dependence of the band gap of the nanomaterials  on the concentration of co-dopants was established. Our findings suggest that the variability of the optical band gap in the ZnO sample containing 4 at.% Al and 2 at.% Cu is a consequence of the manifestation of size quantization  effects. 10.18721/JPM.181.104 538.975 nanostructure engineering sol-gel technology zinc oxide scanning electron microscopy UV-Vis spectroscopy optical band gape https://physmath.spbstu.ru/article/2025.79.4/
CNF RUS 28-33 0000-0002-3336-9176 Ioffe Institute Sorokina Svetlana svsorokina@mail.ioffe.ru 0000-0002-6373-9289 Ioffe Institute Khvostikova Olga olgakhv@mail.ioffe.ru Ioffe Institute Kornienko Polina polina.kornienko.2003@mail.ru 0000-0003-0107-504X Ioffe Institute Khvostikov Vladimir vlkhv@scell.ioffe.ru Frontal surface passivation of the photovoltaic converter based on narrow-band materials Passivation of the photosensitive surface of germanium and gallium antimonide with amorphous and polycrystalline silicon has been carried out. Using the passivating Si-films, the laser radiation converters for a wavelength of λ ~ 1550 nm are developed and manufactured. The proposed method allows developing the converters with high values of output parameters and shortens the technological cycle compared to two-stage diffusion into an open surface. 10.18721/JPM.181.105 629.7.064.56 passivation photovoltaic converter Ge GaSb https://physmath.spbstu.ru/article/2025.79.5/
CNF RUS 34-39 0000-0002-4513-6345 Ruzhevich Maxim max.ruzhevich@niuitmo.ru Mynbaev Karim mynkad@mail.ioffe.ru St. Petersburg Electrotechnical University "LETI" Firsov Dmitrii d.d.firsov@gmail.com
St. Petersburg, Russian Federation
 St. Petersburg Electrotechnical University "LETI" Chumanov Ivan chumanov2000@yandex.ru
St. Petersburg, Russian Federation
 St. Petersburg Electrotechnical University "LETI" Komkov Oleg oleg_sergeevich@mail.ru
St. Petersburg, Russian Federation
 0000-0001-7722-6428 Varavin Vasiliy varavin@isp.nsc.ru 0000-0002-9910-2028 Yakushev Maxim yakushev@isp.nsc.ru Optical characteristics of Hg0.7Cd0.3Te films with etched graded-gap surface layer In this work, the influence of the surface graded-gap layer on the optical properties of epitaxial Hg0.7Cd0.3Te films was studied using optical methods. Photoluminescence and photoreflectance were used to establish a change in the  optical response from samples after etching off the graded-gap layer. It was shown that its presence manifests itself differently in the optical signal from as-grown and annealed films. 10.18721/JPM.181.106 551.510.411 solid solutions HgCdTe photoluminescence photoreflectance https://physmath.spbstu.ru/article/2025.79.6/
CNF RUS 40-45 Peter the Great St. Petersburg Polytechnic University Ladanova Julia julia_ladanova@mail.ru Peter the Great St. Petersburg Polytechnic University Zagorodneva Valeria zagorodnevaleria@gmail.com 0000-0003-1488-8613 Ioffe Institute Dvortsova Polina p.dvortsova@mail.ioffe.ru Ioffe Institute Suturin Sergey Suturin@mail.ioffe.ru
St. Petersburg, Russian Federation
 0000-0001-5547-9387 Alferov University Fedorov Vladimir fedorov_vv@spbstu.ru Peter the Great St. Petersburg Polytechnic University Ustinov Alexander ustinov@physics.spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
 Ioffe Institute Sakharov Vladimir v.i.sakharov@mail.ioffe.ru Sokolov Nikolai nsokolov@fl.ioffe.ru Structural and electrophysical properties of barium titanate epitaxial films One of the rapidly developing areas of nanophotonics is the creation of integrated optical circuits for the operation of ultrafast, energy-efficient devices. Electro-optical modulators are the integral part of such systems. The possibility of  optical modulation is provided by the electro-optical effect occurring in the waveguide structure and providing the opportunity to manage the optical properties of waveguide materials under the influence of electric fields. Barium  titanate BaTiO3 (BTO) exhibits one of the largest known electro-optical coefficients, which makes it an ideal candidate for use in photonic integrated circuit modulators. This work is dedicated to the fabrication of BTO/MgO(001) epitaxial heterostructures and to characterization of their structural and electrophysical properties. The substrate material was chosen based on the difference in the refractive indices of BTO and MgO. The growth was carried out by  pulsed laser deposition (PLD). The crystal structure and epitaxial relations in the grown heterostructures were monitored in situ during growth using high-energy electron diffraction. To study the dependence of the BTO layer  polarization on the external electric field, test samples with a buffer conducting layer of SrRuO3 and gold contacts deposited on top were grown. Measurements of the electrophysical properties were performed using a two-probe  mode. 10.18721/JPM.181.107 538.9 electro-optical modulators waveguides barium titanate Pockels effect https://physmath.spbstu.ru/article/2025.79.7/
CNF RUS 46-51 Arteev Dmitri ArteevDS@mail.ioffe.ru Sakharov Alexey val@beam.ioffe.rssi.ru Nikolaev Andrei Aen@mail.ioffe.ru Zavarin Evgenii EZavarin@mail.ioffe.ru Nikitina Ekaterina mail.nikitina@mail.ru Tsatsulnikov Andrey andrew@beam.ioffe.ru Sheet resistance of AlGaN/GaN heterostructures with barriers of increased Al content In this work, a set of AlxGa1−xN/GaN heterostructures with increased aluminum mole fraction up to 0.30–0.45 was grown using metalorganic vapor-phase epitaxy on silicon substrates. It was shown that the dependence of sheet  resistance on the aluminum mole fraction had a minimum at x ~ 0.37. The lowest experimentally obtained value was 236 Ω/sq., which, to the best of our knowledge, is the lowest reported value for AlGaN/GaN structures grown on Si  substrates. 10.18721/JPM.181.108 621.315.592 nitrides two-dimensional electron gas HEMT https://physmath.spbstu.ru/article/2025.79.8/
CNF RUS 52-57 Ioffe Institute Zedomi Tamara Ester tomazedomi@mail.ru Ioffe Institute Belova Daria belova_dd@voenmeh.ru 0000-0001-8767-9252 Ioffe Institute Kotova Lyubov kotova@mail.ioffe.ru Kochereshko Vladimir Vladimir.Kochereshko@mail.ioffe.ru Magnetic field effect on interface states in ZnSe/BeTe quantum well structures with no common atom Photoluminescence (PL) spectra of type-II ZnSe/BeTe quantum wells with no common atom at interfaces were investigated under magnetic fields up to 45 T, focusing on the regions of direct and indirect interband optical transitions.  Interface carrier states were observed in indirect transition spectral regions. Diamagnetic shift constants and g-factors were extracted, allowing to calculate state localization on the interface plane. As the magnetic field increased, a  relative redistribution of indirect and interface exciton PL line intensities was found. This redistribution can be explained by blocking interface state population channels through the BeTe layer. A model describing the dependence of  PL intensities on magnetic field was developed and found to fit experimental data well. 10.18721/JPM.181.109 538.958 quantum well interface g-factor excitons https://physmath.spbstu.ru/article/2025.79.9/
CNF RUS 58-66 Peter the Great St. Petersburg Polytechnic University Melentyev Grigori gamelen@spbstu.ru Peter the Great St. Petersburg Polytechnic University Vinnichenko Maxim mvin@spbstu.ru Peter the Great St. Petersburg Polytechnic University Karaulov Danila karaulov.da@edu.spbstu.ru
St. Petersburg, Russian Federation
 J-6066-2013 35403302800 0000-0003-3947-4994 Peter the Great St. Petersburg Polytechnic University Firsov Dmitry firsov.da@spbstu.ru
Russia, 195251, St.Petersburg, Polytechnicheskaya, 29
 Effect of different types of phonons on the two-dimensional electron gas heating at GaN/AlGaN heterointerface In this paper, we study the two-dimensional electron heating effects in an lectric field in a quantum well at a GaN/AlGaN heterointerface. The energy loss rates of two-dimensional electrons due to interaction with interface and half-space optical phonons were calculated. The calculations took into account the dynamical screening of polarization potential by free electrons and the hot-phonon effect. The energies of three interface phonon modes were calculated.  Calculation of the energy loss rate related to the interface phonon scattering showed that at electron temperatures above 70 K, the main contribution to scattering is made by the high energy mode of 96.2 meV. If the electron  temperature exceeds 40 K, then the contribution of half-space phonons to energy losses exceeds the contribution of interface phonons. The field dependence of the electron temperature was calculated taking into account various  effects, affecting the charge carrier heating. The calculated electron temperature reaches its highest values with simultaneous consideration of dynamical screening and the hot-phonon effect. The spectra of radiation emitted by hot two-dimensional electrons were calculated for several electron temperatures. 10.18721/JPM.181.110 535.3 interface phonons half-space phonons dynamical screening hot-phonon effect two-dimensional electrons electron heating gallium nitride https://physmath.spbstu.ru/article/2025.79.10/
CNF RUS 67-71 Rzhanov Institute of Semiconductor Physics Betke Igor i.betke@g.nsu.ru Rzhanov Institute of Semiconductor Physics Siberian Branch of RAS Strygin Ivan vanya-91@yandex.ru
Novosibirsk, Russian Federation
 Rzhanov Institute of Semiconductor Physics Kolosovsky Eugeny kolos@isp.nsc.ru Rzhanov Institute of Semiconductor Physics Siberian Branch of RAS Bykov Alexey bykov@isp.nsc.ru
Novosibirsk, Russian Federation
 Effect of illumination on positive magnetoresistance of high-mobility two-dimensional electron gas in GaAs/AlAs heterostructure In this paper, we study the effect of red LED illumination on the positive magnetoresistance of a high-mobility two-dimensional electron gas in a selectively doped GaAs/AlAs heterostructure at a temperature T = 4.2 K in magnetic  fields B < 1 T. We observe a significant increase in the positive magnetoresistance as a result of illumination. It is shown that illumination-induced increase in the positive magnetoresistance in the two-dimensional electron system  under study is due to an increase in the quantum lifetime. 10.18721/JPM.181.111 538.9 magnetoresistance two-dimensional electron gas GaAs quantum well AlAs/GaAs short-period superlattice https://physmath.spbstu.ru/article/2025.79.11/
CNF RUS 72-76 0000-0002-6540-0385 Moscow Institute of Physics and Technology (MIPT) Bakhmetiev Maxim bakhmetiev.maxim@gmail.com Moscow Institute of Physics and Technology (MIPT) Chiglintsev Emil chiglintsev.eo@phystech.edu
Moscow, Russian Federation
 Moscow Institute of Physics and Technology (MIPT) Barulina Elena e.barulina@rqc.ru Moscow Institute of Physics and Technology (MIPT) Shevyakova Ksenia sheviakova.kv@phystech.edu Center for Neurophysics and Neuromorphic Technologies Morozov Alexander alexander.m.dmi@gmail.com Moscow Institute of Physics and Technology (MIPT) Kleshch Viktor klesch@polly.phys.msu.ru Moscow Institute of Physics and Technology (MIPT) Chernov Alexander a.chernov@rqc.ru
Moscow, Russian Federation
 Analysis of charge transport in a tunnel junction based on magnetic insulator CrCl3 This paper investigates charge transport in tunnel junctions based on the two-dimensional magnetic insulator chromium trichloride (CrCl3). The tunneling device, consisting of a 9 nm thick CrCl3 flake sandwiched between graphite  contacts, exhibited two distinct tunneling mechanisms: direct tunneling at low voltages and Fowler − Nordheim tunneling at high voltages. At low temperatures, tunneling was suppressed by antiparallel spin alignment in CrCl3 layers,  while at high temperatures above 18 K the effective tunnel barrier height decreased and sharp current increase was observed. An unusual increase in the barrier height was observed in the temperature range of 20–23 K. Obtained  results highlight the enhanced spin filtering effects in thicker CrCl3-based tunnel junctions, providing insights for spintronic applications. 10.18721/JPM.181.112 537.9 tunnel junction magnetic insulator chromium trichloride antiferromagnetism charge transport https://physmath.spbstu.ru/article/2025.79.12/
CNF RUS 77-82 0009-0006-0923-1501 Peter the Great St. Petersburg Polytechnic University Kozko Ivan
St. Petersburg, Russian Federation
 0009-0005-0777-6746 Alferov University Karaseva Elizaveta
St. Petersburg, Russian Federation
 Alferov University Svinkin Nikita nik-svinkin@mail.ru
St. Petersburg, Russian Federation
 0009-0003-4890-683X ITMO University Rider Maxim
St. Petersburg, Russian Federation
 0000-0001-6869-1213 Alferov University Vyacheslavova Ekaterina cate.viacheslavova@yandex.ru Gridchin Vladislav gridchinvo@gmail.com 0000-0001-5547-9387 Alferov University Fedorov Vladimir fedorov_vv@spbstu.ru 0000-0002-3469-5897 Alferov University Kondratev Valeriy kvm_96@mail.ru
St. Petersburg, Russian Federation
 0000-0001-7223-7232 Moscow Institute of Physics and Technology (National Research University) Bolshakov Alexey acr1235@mail.ru
Moscow, Russian Federation
 Fluorescence of hybrid structures based on carbon dots and GaP, GaN, Si nanowires This work presents a method for evaluating the specific emission intensity of carbon dots (CDs) on the surface of epitaxial GaP, GaN and etched Si nanowires (NWs) using confocal fluorescence microscopy. The obtained results  characterize GaP NWsbased hybrid structures as exhibiting the highest specific emission intensity under unified CDs deposition algorithm. The interaction model between CDs and the NWs surface is investigated and the influence of  the NWs crystalline structure on the photoluminescence of CDs is analyzed. The results are of interest for the synthesis of hybrid light-emitting structures whose properties can be controlled by varying the NWs material, structure,  and geometry. 10.18721/JPM.181.113 538.975 carbon dots fluorescent agents gallium phosphide gallium nitride silicon nanowires hybrid structures https://physmath.spbstu.ru/article/2025.79.13/
CNF RUS 83-87 Alferov University Sharov Vladislav vl_sharov@mail.ru
St. Petersburg, Russian Federation
 Polarized Raman scattering in strained GaN nanowires GaN nanowires are important building blocks for next-generation UV- and visible range optoelectronic devices whose performance can be boosted via strain engineering. This necessitates the investigation of physical phenomena in  nanowires induced by elastic strains. The present paper studies deformation-induced features of Raman spectrum in individual horizontal GaN nanowire, in which elastic strain was created with AFM probe. Two-dimensional mapping  of the Raman signal is carried out with submicron spatial resolution in two polarization configurations. The Raman modes shapes and intensities are analyzed with respect to strain level and polarization of excitation. Deformation potential constants of A1(TO) and E2H modes are estimated from strain-induced spectrum broadening. 10.18721/JPM.181.114 538.911 Gallium nitride GaN nanowires Raman scattering strain https://physmath.spbstu.ru/article/2025.79.14/
CNF RUS 88-94 0009-0000-0094-9986 Russian-Armenian University Avetisyan Arman arman.avetisyan@rau.am Peter the Great St. Petersburg Polytechnic University Vinnichenko Maxim mvin@spbstu.ru Russian-Armenian University Hakobyan Eduard eduard.hakobyan@rau.am Impact of geometry on semiconductor quantum dots optical properties A blend of finite element method and effective mass approximation is used to analyze the optical properties of the following nanostructures, namely nanoplatelets, nanorods and other structures. This theoretical research is directed  towards the effects of structural asymmetry on size quantization, absorption coefficients, and photoluminescence. The introduction of asymmetry in these nanostructures led to significant shifts in the absorption spectra and marked  variations in photoluminescence intensity compared to the symmetric ones. The results provided in this work will be that even slight deviations from symmetry can provide rise to radical alterations in optical behavior, which turn out critical in its design and optimization when thinking of a host of optoelectronic applications. The overall results further suggest that better and tailor-made design strategies in the engineering of nanomaterials can be achieved with an  improved understanding of the interplay between the structural features and optical properties. In general, the present research contributes to the growing understanding directed at the functional enhancement of nanostructures  through controlled structural manipulation. 10.18721/JPM.181.115 535.3 finite element method effective mass approximation nanostructures structural asymmetry absorption photoluminescence nanostar nanotadpole https://physmath.spbstu.ru/article/2025.79.15/
CNF RUS 95-99 0009-0008-1846-1979 Zhivopistsev Alexander Prokhorov General Physics Institute, RAS Romshin Alexey alex_31r@mail.ru
Moscow, Russian Federation
 Prokhorov General Physics Institute RAS Pasternak Dmitrii dg.pasternak@physics.msu.ru Институт исследований и разработки материалов, A*STAR Kalashnikov Dmitry dmitry_kalashnikov@imre.a-star.edu.sg Vereshchagin Institute of High Pressure Physics RAS Bagramov Rustem bagramov@mail.ru
Moscow, Russian Federation
 Vereshchagin Institute of High Pressure Physics RAS Filonenko Vladimir vpfil@mail.ru
Moscow, Russian Federation
 Prokhorov General Physics Institute, RAS Vlasov Igor vlasov@nsc.gpi.ru
Moscow, Russian Federation
 Narrow-band fluorescence of silicon-vacancy color centers in nanodiamonds placed in ring microresonator The paper reports on the photon emission properties of ‘silicon-vacancy’ (SiV) color centers in nanodiamonds synthesized by High−Pressure High−Temperature (HPHT), integrated with a high-quality factor (Q > 10,000) Si3N4 ring  microresonator coupled to a waveguide. The feasibility of collecting SiV-emission through the waveguide is demonstrated, marking a crucial step towards the integration of quantum emitters in photonic circuits. Zero phonon line of  SiV-fluorescence, recorded from the waveguide under confocal laser excitation, revealed a full width at half maximum of ~0.3 nm, which is 19 times narrower than in case of free space linewidth, and a Q-factor of approximately 2,500.  In addition, efficient excitation of SiV-centers in nanodiamonds by laser pumping through the waveguide is demonstrated, underscoring the practicality of waveguide-coupled microresonators for on-chip quantum photonic  applications. Finally, perspectives and limitations of such a platform for integrated optics and quantum communication technologies is discussed. 10.18721/JPM.181.116 535.3 nanodiamonds color centers microcavities integrated nanophotonics https://physmath.spbstu.ru/article/2025.79.16/
CNF RUS 100-104 0000-0003-1835-1629 Alferov University Shubina Kseniia rein.raus.2010@gmail.com
St. Petersburg, Russian Federation
 Alferov University Sinitskaya Olesya olesia-sova@mail.ru
St. Petersburg, Russian Federation
 Enns Yakov ennsjb@gmail.com Mizerov Andrey andreymizerov@rambler.ru Nikitina Ekaterina mail.nikitina@mail.ru Near-UV detectors based on ultrathin GaN epitaxial layers Various nanostructures and ultrathin layers attract increasing attention for the fabrication of different sensors and photodetectors. In this paper, near-UV photodetectors based on ultrathin gallium nitride layers grown by molecular  beam epitaxy with nitrogen plasma activation on sapphire substrates are presented. Two types of photodetectors are fabricated: metal−semiconductor−metal detectors and Schottky photodiodes, and their characteristics are studied.  It is shown that using a silicon dioxide layer in the detector design allows not only to reduce the dark current of such devices, but also to drastically increase the photocurrent of the detectors. Thus, gallium nitride surface passivation  with silicon dioxide allows to increase the photocurrent to the dark current ration of the detectors, and therefore has a positive effect on the performance of the photosensitive devices based on ultrathin gallium nitride layers. 10.18721/JPM.181.117 621.383.52 gallium nitride photodetectors near-UV range dark current photocurrent https://physmath.spbstu.ru/article/2025.79.17/
CNF RUS 105-110 0009-0007-1056-5100 ITMO University Kirilenko Iaroslav idkirilenko@itmo.ru 0000-0002-4513-6345 Ruzhevich Maxim max.ruzhevich@niuitmo.ru 0000-0002-9989-3843 Romanov Viacheslav romanovvv@mail.ioffe.ru Ioffe Institute Moiseev Konstantin mkd@iropt2.ioffe.ru
St. Petersburg, Russian Federation
 0000-0001-5987-3357 ITMO University Dorogov Maksim mvdorogov@itmo.ru Ioffe Institute of RAS Tomkovich Maria marya.tom83@gmail.com St. Petersburg Electrotechnical University "LETI" Firsov Dmitrii d.d.firsov@gmail.com
St. Petersburg, Russian Federation
 St. Petersburg Electrotechnical University "LETI" Chumanov Ivan chumanov2000@yandex.ru
St. Petersburg, Russian Federation
 St. Petersburg Electrotechnical University "LETI" Komkov Oleg oleg_sergeevich@mail.ru
St. Petersburg, Russian Federation
 Mynbaev Karim mynkad@mail.ioffe.ru Influence of disordering in InAsSbP barrier layers on the characteristics of InAsSb-based LEDs Energy-dispersive X-ray spectroscopy, optical reflectance and photoluminescence were used to study the properties of InAsSbP barrier layers in InAsSb/InAsSbP heterostructures (HSs) and their effect on the performance of HSs. A  deviation of the chemical composition of the layers from the specified value and acceptor-like states in their bandgap were found. These features defined the nature of radiative transitions in the HSs. 10.18721/JPM.181.118 538.91 solid solutions InAsSbP heterostructures chemical composition photoluminescence https://physmath.spbstu.ru/article/2025.79.18/
CNF RUS 111-116 0009-0008-5664-6130 Ioffe Institute Malevskaya Anastasia anmalevskaya@mail.ioffe.ru Mintairov Mikhail mamint@mail.ioffe.ru Ioffe Institute Evstropov Valerii vvevstropov@gmail.com
St. Petersburg, Russian Federation
 Ioffe Institute Malevskiy Dmitriy dmalevsky@scell.ioffe.ru
St. Petersburg, Russian Federation
 Ioffe Institute Malevskaya Aleksandra amalevskaya@mail.ioffe.ru Kalyuzhniy Nikolai nickk@mail.ioffe.ru Optimizing the front contact grid parameters of рhotovoltaic laser power converters The paper presents a method for calculating the optimal parameters of the front contact grid of photovoltaic converters (PC). This method extends a previously developed tube model of current spreading and allows taking into  account the thickness, height, and resistivity of the contact fingers, as well as shading effects on the photoactive surface. The method was applied to high-efficient AlGaAs/GaAs photovoltaic converters of laser radiation (λ = 800–850  nm) fabricated with different front metal grid in which contact pitch varied from 100 to 140 μm. Results show that the improved model precisely describes the experimental current-voltage (I–V) curves of all PCs. Reducing the metal finger height to 4 μm increases efficiency by 1.1% for the PC with 140 μm contact pitch and by 0.7% for the one with 100 μm contact pitch. 10.18721/JPM.181.119 621.315.592 photovoltaic converters spreading resistance contact resistance I–V curve electroluminescence https://physmath.spbstu.ru/article/2025.79.19/
CNF RUS 117-121 0000-0002-9448-2471 Connector Optics LLC Gladyshev Andrey andrey.gladyshev@connector-optics.com
St. Petersburg, Russian Federation
 ITMO University Andryushkin Vladislav vvandriushkin@itmo.ru
St. Petersburg, Russian Federation
 Ioffe Institute Kovach Yakov yakovachyakov@gmail.com
St. Petersburg, Russian Federation
 Babichev Andrei scientific.ocean@gmail.com. JSC OKB-Planeta Voropaev Kirill kirill.voropaev@novsu.ru
V. Novgorod, Russian Federation
 0000-0002-0789-4241 Alferov University Egorov Anton anton.egorov@connector-optics.com
St. Petersburg, Russian Federation
 ITMO University Karachinsky Leonid lkarachinsky@itmo.ru
St. Petersburg, Russian Federation
 Increase in the modulation bandwidth of the high-speed VCSEL 1550 nm by active region p-type doping The effect of active region p-type doping on the static and dynamic parameters of vertical cavity surface-emitting lasers (VCSEL) operating at a wavelength of 1550 nm is investigated. The p-type doped active region heterostructures  of the lasers exhibits a two-fold increase in the peak photoluminescence intensity, compared to the undoped heterostructure. This increase can be attributed to an increase in differential gain. The VCSELs demonstrate single-mode  operation with a nearly identical threshold current of 1.9 to 2.0 mA at room temperature, producing a maximum output power of 5.5 mW for the undoped device and 3.5 mW for the p-type doped laser. This reduction in output power  can be attributed to increased free carrier absorption. As a result of p-doping, an increase in the modulation bandwidth from 7.2 GHz to 8.9 GHz was achieved. 10.18721/JPM.181.120 621.373.826 vertical cavity surface-emitting laser 1550 nm wafer-fusion molecular-beam epitaxy p-type doping modulation bandwidth https://physmath.spbstu.ru/article/2025.79.20/
CNF RUS 122-127 St. Petersburg Electrotechnical University “LETI” Zyryanova Oksana oksana.zyryanova.2002@gmail.com Nalimova Svetlana sskarpova@list.ru 0000-0002-3469-5897 Alferov University Kondratev Valeriy kvm_96@mail.ru
St. Petersburg, Russian Federation
 0000-0002-9937-9078 St. Petersburg Electrotechnical University “LETI” Bui Cong Doan congdoan6997@gmail.com 0000-0001-6500-5492 St. Petersburg Electrotechnical University "LETI" Moshnikov Vyacheslav vamoshnikov@mail.ru WOx/WS2 nanocomposites for room temperature gas sensors Semiconductor gas sensors are widely used in industry, medicine and environmental monitoring. One of the most important tasks in sensor technology is to reduce the operating temperature of the device, which is possible due to the  optimization of nanostructures, surface modification with catalysts, the manufacture of hybrid or composite nanostructures and the use of ultraviolet or visible light. The purpose of this work is to develop a method for the hydrothermal  synthesis of WOx/WS2 composite nanostructures to create sensor layers operating at room temperature, as well as to study the effect of UV irradiation on the gas-sensitive characteristics of the developed layers. 10.18721/JPM.181.121 621.315.59 gas sensors room temperature nanostructures tungsten oxide tungsten disulfide nanocomposites https://physmath.spbstu.ru/article/2025.79.21/
CNF RUS 128-133 Ioffe Institute Kovach Yakov yakovachyakov@gmail.com
St. Petersburg, Russian Federation
 Ioffe Institute Blokhin Sergei blokh@mail.ioffe.ru
St. Petersburg, Russian Federation
 Ioffe Institute Bobrov Mikhail bobrov.mikh@gmail.com
St. Petersburg, Russian Federation
 0000-0002-3449-8711 Ioffe Institute Blokhin Aleksey Aleksey.Blokhin@mail.ioffe.ru
St. Petersburg, Russian Federation
 0000-0003-2500-1715 Ioffe Institute Maleev Nicolai maleev.beam@mail.ioffe.ru
St. Petersburg, Russian Federation
 0000-0002-2181-5300 Submicron Heterostructures for Microelectronics, Research & Engineering Center, RAS Vasil’ev Alexey
St. Petersburg, Russian Federation
 Effect of temperature on the spectral linewidth of 89X nm-range single-mode VCSELs This paper presents the study of the spectral linewidth of a vertical-cavity surface-emitting lasers in the 89X nm spectral range. The devices demonstrate single-mode lasing with a pronounced stable direction of linear polarization in a  wide temperature range and at all operating currents. The minimum recorded spectral linewidth for the devices under study was 43 MHz at room temperature. It was shown that an increase in external temperature by one hundred  degrees leads to an increase in the minimum spectral line width of the laser by more than four times. At the same time, the spectral linewidth of the vertical-cavity emitting lasers under study is less than 100 MHz at temperatures up to 80°C with an output optical power of more than 150 μW, which demonstrates the promise of using the developed vertical-cavity emitting lasers in compact atomic sensors. 10.18721/JPM.181.122 621.373.8 VCSEL spectral linewidth atomic sensors a-factor https://physmath.spbstu.ru/article/2025.79.22/
CNF RUS 134-139 0000-0003-3341-9388 Novosibirsk State University Cheng Yuzhu chengyuzhu9@gmail.com 0000-0002-6413-0969 Kamaev Gennadiy kamaev@isp.nsc.ru Popov Aleksandr aapopov@mail.ru Volodin Vladimir volodin@isp.nsc.ru Influence of Ge nanolayers on the resistive switching effect in amorphous hydrogenated silicon based structures Resistive switchings in p–i–n structures based on amorphous hydrogenated silicon both with and without inclusions of Ge nanolayers in the i-layer were studied. The structure of the samples was studied using Raman spectroscopy. It  was shown that all layers were amorphous and contained up to 35 atomic % of hydrogen. In the structures with five 6 nm thick Ge nanolayers embedded in the i-layer, separated by layers of undoped 15 nm thick amorphous  silicon, the resistive switching effects are stable and reproducible in the bipolar mode from a high-resistance state to a low-resistance state and backwards. In this case, the resistive switchings occur through several intermediate  stages. This type of switching is typical for multi-bit or analog memristors. It was shown that the intermediate states have high stability. The memory window observed in the experiments grows linearly with increasing limiting current  with good current stability in the OFF state. Thus, the studied p–i–n structures can be used in memristors. 10.18721/JPM.181.123 537.9 amorphous silicon germanium nanolayers memristor multilayer structure p–i–n structure https://physmath.spbstu.ru/article/2025.79.23/
CNF RUS 140-144 Ioffe Institute Soldatenkov Fedor
St. Petersburg, Russian Federation
 Ioffe Institute Pugovkin Alexey a.pugovkin@mail.ioffe.ru Ivanov Anton a-e-ivano-v@yandex.ru Ioffe Institute Malevskiy Dmitriy dmalevsky@scell.ioffe.ru
St. Petersburg, Russian Federation
 Levin Sergey sergiolevin733@gmail.com Dependence of static and dynamic characteristics of high-voltage pulsed p–i–n diodes on the composition of heteroepitaxial AlxGa1−xAs1−ySby base layers Forward current-voltage characteristics and reverse recovery of high-voltage p–i–n diodes based on AlxGa1–xAs1–ySby layers with x ranging from 0 to 0.6 and y ranging from 0 to 0.2, manufactured by liquid-phase epitaxy due to self-doping with background impurities, have been studied. The forward current-voltage characteristics, described as a sum of the recombination current in the space charge region and the diffusion current in the base, have been  observed at low current densities for p0–i–n0 junctions of GaAs, AlxGa1–xAs and AlxGa1–xAs1–ySby with x up to 0.6 and y up to 0.04. The effective lifetime of nonequilibrium charge carriers decreases from ~ 170 ns in GaAs layers to  30–60 ns in the layers of AlxGa1–xAs with x ranging from 0.2 to 0.45 and to 4–12 ns in AlxGa1–xAs1–ySby layers. 10.18721/JPM.181.124 681.782.473 AlGaAsSb heterostructure high-voltage p0–i–n0 junction diode liquid-phase epitaxy reverse recovery of diodes https://physmath.spbstu.ru/article/2025.79.24/
CNF RUS 145-151 Alferov University Svinkin Nikita nik-svinkin@mail.ru
St. Petersburg, Russian Federation
 0000-0002-3469-5897 Alferov University Kondratev Valeriy kvm_96@mail.ru
St. Petersburg, Russian Federation
 Polozkov Roman polozkov@tuexph.stu.neva.ru 0000-0001-8440-494X Alferov University Novikova Kristina novikova_k@spbau.ru
St. Petersburg, Russian Federation
 Zubov Fedor fzubov@hse.ru 0000-0002-8661-4083 Alferov University Mozharov Alexey mozharov@spbau.ru
St. Petersburg, Russian Federation
 0000-0001-7223-7232 Moscow Institute of Physics and Technology (National Research University) Bolshakov Alexey acr1235@mail.ru
Moscow, Russian Federation
 Silicon nanowire based sensorics of acids and bases This work is dedicated to obtaining new data on the adsorption properties of silicon in nanowire (NW) geometry for application in sensors. It has been experimentally shown that silicon without modification can be used for selective  detection of ammonia and hydrochloric acid. Quantum chemistry modeling indicates that during the adsorption of NH3, HCl, and H2O molecules, the electron density redistributes between the adsorbate and the silicon surface,  leading to changes in electrical conductivity of the silicon sample. A model linking the change in the conductivity of the silicon sample with the time during which it is exposed to analyte vapor has been developed. The effective  sticking coefficient for water adsorption on the silicon NW surface was estimated from experimental results and quantum chemical calculations. 10.18721/JPM.181.125 544.723 silicon nanowires ammonia hydrochloric acid DFT adsorption sensorics https://physmath.spbstu.ru/article/2025.79.25/
CNF RUS 152-157 Lomonosov Moscow State University Smirnov Kirill smirnov.ka19@physics.msu.ru Lomonosov Moscow State University Zhaboev Evgeniy zhaboev.ei19@physics.msu.ru Russian Technological University (MIREA) Mitetelo Nikolai nickm@shg.ru Lomonosov Moscow State University Maydykovskiy Anton anton@shg.ru Lomonosov Moscow State University Murzina Tatiana murzina@mail.ru Study of resonator optical properties of perylene microcrystals Microcrystals based on nonlinear organic materials are of great interest for modern photonics, allowing for the formation of miniature optical modules, i.e., resonators, waveguides, connectors, filters, etc., both active and passive.  Such organic semiconductor materials as perylene and its derivatives are currently used in optoelectronics and light-emitting materials industry due to their outstanding properties, for example, high mechanical and thermal stability as well as a high photoluminescence quantum yield. Perylene is a polymorphic crystal with the monoclinic structure that can exist in two phases, alpha or beta, characterized by photoluminescence in yellow or green spectral ranges, respectively. The implementation of resonator structures based on perylene microcrystals for sensorics and microlasers applications seems promising. In this work, resonator properties of perylene microcrystals with the form of  rectangular parallelepipeds (alpha phase) produced by the self-organization technique were studied using nonlinear optical microscopy and spectroscopy methods. It was shown that the two-photon photoexcitation of perylene  microcrystals leads to the appearance of a luminescence spectrum with a mode composition and the localization of the electromagnetic field in certain areas near the crystal faces, which corresponds to the excitation of Fabry – Pérot modes in microstructures. 10.18721/JPM.181.126 535 organic microresonators nonlinear optics photonics https://physmath.spbstu.ru/article/2025.79.26/