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440 results on '"Mintairov, S. A."'

55. Selective Area Epitaxy of InP/GaInP2Quantum Dots from Metal-Organic Compounds.

Author

Vlasov, A. S., Afanasev, K. M., Galimov, A. I., Kalyuzhnyy, N. A., Lebedev, D. V., Malevskaya, A. V., Mintairov, S. A., Rakhlin, M. V., Salii, R. A., Mozharov, A. M., Mukhin, I. S., and Mintairov, A. M.

Subjects
METAL organic chemical vapor deposition, QUANTUM dots, ORGANOMETALLIC compounds, EPITAXY, LITHOGRAPHY
Abstract

Experiments on the growth of self-assembled InP/GaInP2 quantum dots in dielectric mask 0.1–1 μm apertures by MOVPE epitaxy have been carried out. A sequence of operations for the implementation of the lift-off lithography method is proposed and implemented. The possibility of obtaining apertures with 100 nm diameter and less is shown. Combination of thermally deposited SiO2 and wet etching is shown to produce minimal amount of nonradiative defects and results in a stable PL signal from single QDs in the aperture. [ABSTRACT FROM AUTHOR]

Published
2024
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56. Piezoelectric fields and martensitic transition in spontaneously ordered GaInP2/GaAs epi-layers.

Author

Ankudinov, A. V., Bert, N. A., Dunaevskiy, M. S., Galimov, A. I., Kalyuzhnyy, N. A., Mintairov, S. A., Myasoedov, A. V., Pavlov, N. V., Rakhlin, M. V., Salii, R. A., Toropov, A. A., Vlasov, A. S., Pirogov, E. V., Zhukovskyi, M. A., and Mintairov, A. M.

Subjects
SCANNING probe microscopy, OPTICAL measurements, SURFACE potential, ELECTRON microscopy, MICROSCOPY, CRYSTAL lattices
Abstract

The effect of lattice relaxation instability (martensitic transition) on piezoelectric fields (EPE) in spontaneously ordered GaInP2/GaAs epitaxial layers was demonstrated using scanning Kelvin probe microscopy in combination with electron microscopy and optical spectroscopy measurements. The transition manifests itself in the dependence of the surface potential of the epi-layer on the mechanical (cleavage) and thermal (annealing) impacts. This is associated with a switching of the crystal lattice between relaxed and strained martensitic states, corresponding to a change in EPE in the epi-layer. The measured surface potential values (0.2–2.4 V) correspond to EPE within ±100 kV/cm and a strong decrease in |EPE| with increasing layer thickness, indicating the pinning of the Fermi level and piezoelectric doping. Our results open up the prospects for using spontaneously ordered semiconductor alloys to control electronic states in semiconductor nanostructures by controlling their piezoelectric fields. [ABSTRACT FROM AUTHOR]

Published
2024
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73. Evaluation of energy-to-data ratio of quantum-dot microdisk lasers under direct modulation.

Author

Kryzhanovskaya, N. V., Moiseev, E. I., Zubov, F. I., Mozharov, A. M., Maximov, M. V., Kalyuzhnyy, N. A., Mintairov, S. A., Guseva, Yu. A., Kulagina, M. M., Blokhin, S. A., Berdnikov, Yu., and Zhukov, A. E.

Subjects
LASERS, QUANTUM dots, DENSITY currents
Abstract

The energy-to-data ratio (EDR) was evaluated for quantum-dot based microdisk laser directly modulated without external cooling. The experimental values of EDR decrease with decreasing diameter of the microdisk and reach 1.5 pJ/bit for the smallest diameter under study (10.5 μm). In larger microdisks (with a diameter greater than 20 μm), the EDR varies in proportion to the square of the diameter. If this relationship were true for smaller microdisks as well, an EDR value of about 100 fJ would be achieved with a diameter of 4 μm. The observed deviation of EDR from the quadratic dependence on the diameter is associated with an increase in the threshold current density in smaller devices, which in turn may be caused by the contribution of nonradiative recombination on the microresonator sidewalls formed by deep etching. [ABSTRACT FROM AUTHOR]

Published
2019
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74. Photovoltage-induced blockade of charge and spin diffusion in semiconducting thin films.

Author

Park, S., Paget, D., Berkovits, V. L., Ulin, V. P., Alekseev, P. A., Kaliuzhnyi, N. A., Mintairov, S. A., and Cadiz, F.

Subjects
NUCLEAR spin, SEMICONDUCTOR films, THIN films, CARRIER density
Abstract

In semiconductors under tightly-focused photocarrier excitation, the lateral variation of carrier concentration induces a lateral variation of photovoltage. In chemically-passivated p-type GaAs films at 300 K, we show experimentally and theoretically that the photovoltage lateral dependence is able to block the photoelectron diffusion, thus reducing the effective charge diffusion constant by a factor of ≈ 5 with respect to surface-free conditions and producing a self-trapping of photoelectrons. This effect is not present for surface-free and for oxidized samples, for which the photovoltage magnitude is strongly reduced. The photovoltage lateral variation also induces a coupling between charge and spin diffusion. Because of this coupling, the effective spin diffusion constant is significantly larger than the effective charge one. [ABSTRACT FROM AUTHOR]

Published
2019
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77. Temperature stability of small-signal modulation response of WGM microlasers with InGaAs/GaAs quantum well-dots in the active region

Author

Isaev, N K, primary, Moiseev, E I, additional, Fominykh, N A, additional, Kryzhanovskaya, N V, additional, Zubov, F I, additional, Ivanov, K A, additional, Makhov, I S, additional, Mintairov, S A, additional, Kalyuzhnyi, N A, additional, Guseva, Yu A, additional, Maximov, M V, additional, and Zhukov, A E, additional

Published
2021
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89. Piezo-electric fields and state-filling photo-luminescence in natural InP/GaInP2 Wigner molecule structures

Author

Mintairov, A. M., primary, Ankundinov, A. V., additional, Kalyuzhnyy, N. A., additional, Lebedev, D. V., additional, Mintairov, S. A., additional, Pavlov, N. V., additional, Galimov, A. I., additional, Rakhlin, M. V., additional, Salii, R. A., additional, Toropov, A. A., additional, Vlasov, A. S., additional, Barettin, D., additional, der Maur, M. Auf, additional, and Blundell, S. A., additional

Published
2021
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92. Internal loss in diode lasers with quantum well-dots

Author

null Wang Y., null Maximov M. V., null Kornyshov G. O., null Payusov A. S., null Kalyuzhnyy N. A., null Mintairov S. A., null Serin A. A., null Gordeev N. Yu., null Shernyakov Yu. M., null Kryzhanovskaya N. V., null Nadtochiy A. M., and null Zhukov A. E.

Abstract

The internal loss at the lasing threshold were studied experimentally and numerically in laser cavities comprising dense arrays of InGaAs/GaAs quantum dots (quantum well-dots) as a function of the number of their planes and the output loss. Numerical values of the parameters were found that determine the free-carrier absorption in the active region and in the waveguiding layer. The optimal design of the laser diode was determined to achieve the highest external differential efficiency. Keywords: diode lasers, semiconductor nanostructures, internal loss.

Published
2022
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93. Bimodality in the electroluminescence spectra of quantum well-dots InGaAs nanostructures

Author

null Breuer S., null Maximov M. V., null Zhukov A. E., null Kalyuzhnyy N. A., null Mintairov S. A., null Serin A. A., null Nadtochiy A. M., and null Kharchenko A. A.

Abstract

The electroluminescence spectra of waveguiding structures based on quantum well-dots were investigated with polarization resolution in the temperature range of 60-300 K. It is found that the ground state emission consists of two peaks with different degrees of TE-polarization and these peaks are getting closer with temperature decrease. We attribute the bimodality to the existence of two different types of nanoobjects in the active region: the quantum well-dots, which have partially TE-polarized emission, and quantum dots emitting almost fully TE-polarized light. Keywords: Electroluminescence, quantum dots, InGaAs heterostructures, waveguide structures, emission polarization.

Published
2022
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94. Temperature dependencies of radiative and nonradiative carrier lifetimes in InGaAs quantum well-dots

Author

null Znukov A. E., null Kryzhanovskaya N. V., null Maximov M. V., null Kalyuzhnyy N. A., null Mintairov S. A., null Ivanov K. A., null Melnichenko I. A., and null Nadtochiy A. M.

Abstract

Heterostructure with InGaAs/GaAs quantum well-dots was investigated in temperature range 10-300 K using photoluminescence spectroscopy in CW mode as well with time resolution. Obtained decay times were splitted into radiative and nonradiative components of carrier lifetime. It is found that radiative lifetime demonstrates exponential growth with temperature rise, while temperature dependence of nonradiative one is much weaker. Keywords: semiconductors, quantum well-dots, photoluminescence, time resolution, lifetime, temperature dependence.

Published
2022
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95. High efficiency (EQE=37.5%) infrared (850 nm) light-emitting diodes with Bragg and mirror reflectors

Author

null Andreev V. M., null Shvarts M. Z., null Pokrovskii P. V., null Larionov V. R., null Nakhimovich M. V., null Malevskii D. A., null Salii R. A., null Mintairov S. A., null Kalyuzhnyy N. A., and null Malevskaya A. V.

Abstract

Developed and investigated are IR (850 nm) light-emitting diodes based on AlGaAs/Ga(In)As heterostructures grown by the MOCVD technique with multiple quantum wells in the active region and with a double optical reflector consisted of a multilayer Al0.9Ga0.1As/Al0.1Ga0.9As Bragg heterostructure and an Ag mirror layer. Light-emitting diodes with the external quantum efficiency EQE=37.5% at current densities greater than >10 A/cm2 have been fabricated. Keywords: IR light-emitting diode, AlGaAs/GaAs heterostructure, Bragg reflector, InGaAs quantum wells.

Published
2022
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96. A GaInP-based photo-converter of laser radiation with an efficiency of 46.7% at a wavelength of 600 nm

Author

null Kalyuzhnyy N.A., null Shvarts M.Z., null Salii R. A., null Nakhimovich M.V., null Mintairov M.A., null Evstropov V.V., and null Mintairov S. A.

Abstract

GaInP-based laser power converters (LPC) structure grown by MOVPE and device chip design have been optimized for operation under high-power lasers of the green-red spectral range. Light I-V curves records have shown the performance of the LPC at up to 40-50 W/cm2 of incident power densities. The highest level data were obtained for 532, 600, and 633 nm power laser lines: 44.3%, 46.7%, and 40.6% under 13-16 W/cm2, respectively. LPC demonstrated an efficiency of more than 40% at the incident laser radiation power density elevated up to 40-50 W/cm2. Keywords: laser photoconverter, MOVPE, efficiency, spectral response.

Published
2022
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97. Increasing the efficiency of triple-junction solar cells due to the metamorphic InGaAs subcell

Author

null Kalyuzhnyy N. A., null Shvarts M.Z., null Salii R.A., null Nakhimovich M. V., null Mintairov S. A., null Evstropov V. V., and null Mintairov M. A.

Abstract

The efficiency of GaInP/GaAs/InxGa1-xAs triple-junction solar cells obtained by replacing (in the widely used "classical" GaInP / GaAs / Ge heterostructure) the lower germanium with InxGa1-xAs subcell formed using the metamorphic growth technology has been investigated. Based on an original approach, the optimal indium concentration in the narrow-gap subcell has been found. The main parameters of InxGa1-xAs subcells with an indium concentration from x=0.11 to 0.36 were determined and were used to calculate the IV characteristics of GaInP/GaAs/InxGa1-xAs solar cells. It has been determined that at x=0.28 the efficiency of the triple-junction solar cell increases by 3.4% (abs) in comparison with the "classical" solar cell, reaching a value of 40.3% (AM1.5D). Also it has been shown that the efficiency of such solar cells can be increased up to 41%. Keywords: Multi-junction solar cells, photoconverters, metamorphic buffer. M.Z.Shvarts

Published
2022
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98. Investigation of the photoelectric characteristics of GaAs solar cells with different InGaAs quantum dot array positioning in the i-region

Author

null Kalyuzhnyy N. A., null Shvarts M. Z., null Nakhimovich M. V., null Mintairov S. A., null Mintairov M. A., and null Salii R. A.

Abstract

The effect of positioning of the In0.8Ga0.2As quantum dots (QDs) array in the i-region of the solar cell (SC) on its photogenerated current and dark saturation currents, which determine the device operating voltage, have been investigated. It was found out that the indicated photoelectric characteristics depend on the location of the QD array relative to the electric field of the p-n junction. The displacement of the QD array to the boundary of the weakly doped base leads to a decrease in the photogenerated current. But at the same time, the voltage drop effect, which is well-known for nanoheterostructural SC, is minimal. Keywords: solar cells, quantum dots, dark saturation current

Published
2022
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