Zobrazeno 1 - 10
of 76
pro vyhledávání: '"Heikki Helava"'
Autor:
Vitaliy Avrutin, Yu. Makarov, Natalia Izyumskaya, O. Andrieiev, Alexander Usikov, Kai Ding, Heikki Helava, Michael A. Reshchikov, M. Vorobiov
Publikováno v:
Scientific Reports, Vol 10, Iss 1, Pp 1-7 (2020)
Scientific Reports
Scientific Reports
Photoluminescence (PL) was used to estimate the concentration of carbon in GaN grown by hydride vapor phase epitaxy (HVPE). The PL data were compared with profiles of the impurities obtained from secondary ion mass spectrometry (SIMS) measurements. C
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a4835f659a4af8ab856bebe466a9ff81
https://doi.org/10.1038/s41598-020-59033-z
https://doi.org/10.1038/s41598-020-59033-z
Autor:
Oleg Khait, Alexander Roenkov, M V Puzyk, Oleg N. Medvedev, I A Ermakov, Alexander Usikov, Sergey Kurin, A A Antipov, I. S. Barash, Yu.N. Makarov, Heikki Helava, B P Papchenko, Alexey Y. Nikiforov
Publikováno v:
Materials Science Forum. 897:723-726
GaN, GaN/AlGaN and GaN/InGaN-based structures were used to study water photoelectrolysis in KOH-based electrolyte, measurement of current-potential characteristics, investigation of electrode corrosion and for hydrogen generation. The corrosion proce
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::21c669aa60fcc8beec962d8856550d32
https://doi.org/10.4028/www.scientific.net/msf.897.723
https://doi.org/10.4028/www.scientific.net/msf.897.723
Autor:
N. M. Shmidt, Alexander Usikov, Eugene B. Yakimov, Jin Hyeon Yun, In Hwan Lee, Kirill D. Shcherbachev, N. B. Smirnov, S. A. Tarelkin, Yu.N. Makarov, Alexander Y. Polyakov, Heikki Helava, B P Papchenko, O. I. Rabinovich, Sergey Kurin, Sergey Didenko
Publikováno v:
Modern Electronic Materials, Vol 3, Iss 1, Pp 32-39 (2017)
Electrical and luminescent properties of near-UV light emitting diode structures (LEDs) prepared by hydride vapor phase epitaxy (HVPE) were studied. Variations in photoluminescence and electroluminescence efficiency observed for LEDs grown under nomi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c89f4e36d8e9df205f65e6d38acd1dbd
http://www.sciencedirect.com/science/article/pii/S2452177916300688
http://www.sciencedirect.com/science/article/pii/S2452177916300688
Autor:
Filip Tuomisto, J. D. McNamara, Ümit Özgür, Denis Demchenko, Michael A. Reshchikov, R. M. Sayeed, Yu. Makarov, Alexander Usikov, Heikki Helava, null Prozheeva
The investigation and identification of point defects in GaN is crucial for improving the reliability of light-emitting and high-power electronic devices. The RY3 defect with a characteristic emission band at about 1.8 eV is often observed in photolu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::dbec2024e5461ca6c395f33a9f1c065c
https://aaltodoc.aalto.fi/handle/123456789/39790
https://aaltodoc.aalto.fi/handle/123456789/39790
Autor:
Anton E. Chernyakov, E. I. Shabunina, V. G. Sidorov, Yu.N. Makarov, N. M. Shmidt, Heikki Helava, N. A. Talnishnikh, V. N. Petrov, Alexander Usikov
Publikováno v:
Semiconductors. 50:1173-1179
It is shown that a three-dimensional fractal–percolation system is formed in nanomaterials of light-emitting InGaN/GaN and AlGaN/GaN structures in the presence of conducting extended defects and local inhomogeneities of the composition of the solid
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cbb1e53d867a97b3c6e5071184f56de5
https://doi.org/10.1134/s1063782616090207
https://doi.org/10.1134/s1063782616090207
Autor:
B P Papchenko, Alexey Y. Nikiforov, Heikki Helava, Alexander Usikov, Yu.N. Makarov, Michael Puzyk
Publikováno v:
American Journal of Applied Sciences. 13:845-852
Direct water photoelectrolysis using III-N materials is a promising way for hydrogen production. GaN/AlGaN based p-n structures were used as working electrodes in a photoelectrochemical process to investigate the material etching (corrosion). The str
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c834b5e60c1d0d69d9d7baffe68c0548
https://doi.org/10.3844/ajassp.2016.845.852
https://doi.org/10.3844/ajassp.2016.845.852
Autor:
S. A. Tarelkin, Yu.N. Makarov, Jin Hyeon Yun, O. I. Rabinovich, N. B. Smirnov, Eugene B. Yakimov, Alexander Y. Polyakov, N. M. Shmidt, B P Papchenko, Alexander Usikov, In Hwan Lee, Kirill D. Shcherbachev, Heikki Helava, Sergey Didenko, Sergey Kurin
Publikováno v:
Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering. 19:75-86
Electrical and luminescent properties of near−UV light emitting diode structures (LEDs) prepared by hydride vapor phase epitaxy (HVPE) were studied. Variations in photoluminescence and electroluminescence efficiency observed for LEDs grown under no
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e0aab1c9de9dc3ecf61c4e70a85d4a2e
https://doi.org/10.17073/1609-3577-2016-2-75-86
https://doi.org/10.17073/1609-3577-2016-2-75-86
Autor:
M V Puzyk, Alexey Y. Nikiforov, Heikki Helava, B. P. Papchenko, Alexander Usikov, Yu. V. Kovaleva, Yu.N. Makarov
Publikováno v:
Technical Physics Letters. 42:482-485
Specific features of etching of GaN/AlGaN p–n structures in a KOH-based electrolyte have been studied. It was found that the corrosion process first passes across p layers through vertical channels associated with threading structural defects. Then
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c8179cb843cad74e362e893d9459e4b9
https://doi.org/10.1134/s1063785016050151
https://doi.org/10.1134/s1063785016050151
Publikováno v:
Materials Science Forum. 858:1149-1152
Graphene films were grown on SiC substrates by annealing in vacuum or in Ar flow. Gas sensors based on graphene films were made and tested on response to nitrogen dioxide. Graphene film is used in the sensor. The graphene film grown by annealing in A
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::031cee5f30a77760190c5db26aa7ff34
https://doi.org/10.4028/www.scientific.net/msf.858.1149
https://doi.org/10.4028/www.scientific.net/msf.858.1149
Autor:
Alexander Usikov, A A Antipov, Oleg N. Medvedev, I. S. Barash, Yu.N. Makarov, Sergey Kurin, Heikki Helava, Alexander Roenkov, Oleg Khait
Publikováno v:
Materials Science Forum. 858:1198-1201
Hydride Vapor Phase Epitaxy (HVPE) was used to grow 1-4 μm thick undoped GaN layers on 4H-SiC and sapphire substrates. To adjust mechanical strain and crack formation in the GaN/SiC samples, the AlGaN-based buffer layer was grown at low temperature
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ac75a0446d76a42bda44c8f957664402
https://doi.org/10.4028/www.scientific.net/msf.858.1198
https://doi.org/10.4028/www.scientific.net/msf.858.1198