Zobrazeno 1 - 10
of 75
pro vyhledávání: '"T, Törmä"'
Publikováno v:
Spectrochimica Acta Part B: Atomic Spectroscopy. 119:36-40
X-ray spectroscopy instruments lose part of their performance due to the lack of suitable components for soft X-ray region below 1 keV. Therefore, in the analysis of low atomic number elements including lithium, beryllium, boron and carbon instrument
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2c560a8ed2f9a7d0e5709dd940223c02
https://doi.org/10.1016/j.sab.2016.03.007
https://doi.org/10.1016/j.sab.2016.03.007
Autor:
Lauri Kilpi, J. Heino, Edward Hæggström, Maria Berdova, Jari Koskinen, Tuomo Ylitalo, Helena Ronkainen, Ivan Kassamakov, Sami Franssila, Pekka T. Törmä
Publikováno v:
Berdova, M, Ylitalo, T, Kassamakov, I, Heino, J, Törmä, P T, Kilpi, L, Ronkainen, H, Koskinen, J, Hæggström, E & Franssila, S 2014, ' Mechanical assessment of suspended ALD thin films by bulge and shaft-loading techniques ', Acta Materialia, vol. 66, pp. 370-377 . https://doi.org/10.1016/j.actamat.2013.11.024
We assessed mechanical properties of free-standing atomic-layer-deposited (ALD) Al2O3 thin films, mixed oxide (AlxTiyOz) films and Al2O3/TiO2 nanolaminates (75 and 200 nm). Using bulge and microelectromechanical system shaft-loading techniques, we ev
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::018aaacf75ed697ff185e1fb723f831a
https://doi.org/10.1016/j.actamat.2013.11.024
https://doi.org/10.1016/j.actamat.2013.11.024
Autor:
Markku Sopanen, Sakari Sintonen, Harri Lipsanen, Muhammad Ali, Lauri Riuttanen, Sami Suihkonen, Pekka T. Törmä, Olli Svensk
Publikováno v:
Journal of Crystal Growth. 370:42-45
In this paper we report on the MOCVD growth and characterization of GaN structures and InGaN single quantum wells grown on pillar patterned GaN/sapphire templates. During the regrowth a network of voids was intentionally formed at the interface of sa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a34f3e3ffd0508424aa7c2c2c7af08fc
https://doi.org/10.1016/j.jcrysgro.2012.08.045
https://doi.org/10.1016/j.jcrysgro.2012.08.045
Autor:
Jari Kostamo, Harri Lipsanen, Pekka T. Törmä, Marco Mattila, Heikki Sipila, Marcos Bavdaz, Esa Kostamo, Nick Nelms, Christian Laubis, Brian Shortt, Pasi Kostamo
Publikováno v:
IEEE Transactions on Nuclear Science. 60:1311-1314
We have demonstrated the fabrication of ultra-thin Si fine grid supported silicon nitride X-ray windows. These X-ray windows exhibit unequaled transmission of soft X-rays, high strength and excellent thermal stability. Measured soft X-ray transmissio
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::d2b14e73cfeea71c65114b319865ceb2
https://doi.org/10.1109/tns.2013.2243754
https://doi.org/10.1109/tns.2013.2243754
Autor:
Maxim A. Odnoblyudov, Sami Suihkonen, Pekka T. Törmä, Vladislav E. Bougrov, Olli Svensk, Alexey E. Romanov, Muhammad Ali, Markku Sopanen, Harri Lipsanen
Publikováno v:
Journal of Crystal Growth. 315:188-191
We present the results of GaN re-growth on hexagonally patterned GaN templates. Sapphire was used as the original substrate and the samples were grown by metalorganic vapor phase epitaxy (MOVPE). The re-growth on the patterned templates results in th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cfda2430aa768672a0d5974a84fa0cde
https://doi.org/10.1016/j.jcrysgro.2010.08.055
https://doi.org/10.1016/j.jcrysgro.2010.08.055
Autor:
Pekka T. Törmä, Oili Ylivaara, Sami Franssila, Maria Berdova, Ville Rontu, Riikka L. Puurunen
Publikováno v:
Berdova, M, Ylivaara, O M E, Rontu, V, Törmä, P T, Puurunen, R L & Franssila, S 2015, ' Fracture properties of atomic layer deposited aluminum oxide free-standing membranes ', Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, vol. 33, no. 1, 01A106 . https://doi.org/10.1116/1.4893769
The fracture strength of Al2O3 membranes deposited by atomic layer deposition at 110, 150, 200, and 300 °C was investigated. The fracture strength was found to be in the range of 2.25–3.00 GPa using Weibull statistics and nearly constant as a func
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ad574d6ff9b1065377e644f611771ca7
https://cris.vtt.fi/en/publications/49e90d75-c1bf-4adf-82cb-4154657566aa
https://cris.vtt.fi/en/publications/49e90d75-c1bf-4adf-82cb-4154657566aa
Autor:
Filip Tuomisto, Sami Suihkonen, Pekka T. Törmä, Markku Sopanen, Muhammad Ali, J.-M. Mäki, Olli Svensk
We have applied positron annihilation spectroscopy to study 400 – 500 nm InGaN-based LED structures, as well as InGaN and AlGaN materials with varying In and Al contents. We find that the effect of adding In to GaN on the annihilation parameters ob
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e3b3deb8322a7aedbee4a8d5270b4a83
https://aaltodoc.aalto.fi/handle/123456789/26997
https://aaltodoc.aalto.fi/handle/123456789/26997
Publikováno v:
Kolari, K, Vehmas, T, Svensk, O, Törmä, P & Aalto, T 2009, ' Smoothing of microfabricated silicon features by thermal annealing in reducing or inert atmospheres ', Physica Scripta, vol. 2010, no. T141, 014017 . https://doi.org/10.1088/0031-8949/2010/T141/014017
Kolari, K, Vehmas, T, Svensk, O, Törmä, P & Aalto, T 2010, ' Smoothing of microfabricated silicon features by thermal annealing in reducing or inert atmospheres ', Physica Scripta, vol. 2010, no. T141, 014017 . https://doi.org/10.1088/0031-8949/2010/T141/014017
Kolari, K, Vehmas, T, Svensk, O, Törmä, P & Aalto, T 2010, ' Smoothing of microfabricated silicon features by thermal annealing in reducing or inert atmospheres ', Physica Scripta, vol. 2010, no. T141, 014017 . https://doi.org/10.1088/0031-8949/2010/T141/014017
In this work, high-temperature annealing of reactive ion etched silicon microstructures in H2 and Ar gases is studied. Three types of structural features were etched with four different masks into lang100rang-oriented silicon wafers. Scanning electro
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef7d14eee76386dd2cd8e2aa5e48c07f
https://cris.vtt.fi/en/publications/37783937-06f7-4469-b597-cace23ab74cf
https://cris.vtt.fi/en/publications/37783937-06f7-4469-b597-cace23ab74cf
Autor:
Pekka T. Törmä, Leonid E. Vorobjev, Vadim A. Shalygin, Sami Suihkonen, A. V. Antonov, A. V. Andrianov, A. O. Zakharyin, V. I. Gavrilenko, G. A. Melentyev, D. A. Firsov, A. N. Sofronov, Muhammad Ali, Harri Lipsanen, V. Yu. Panevin
We report on the observation and experimental studies of impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field. The terahertz electroluminescence is observed in a wide range of doping levels (at noncompensated
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::af69c80ec7d16a0b19bf59d4309b3969
https://aaltodoc.aalto.fi/handle/123456789/15893
https://aaltodoc.aalto.fi/handle/123456789/15893
Autor:
Maxim A. Odnoblyudov, Pekka T. Törmä, Harri Lipsanen, Sami Suihkonen, M Kruse, Markku Sopanen, Lauri Riuttanen, Alexey E. Romanov, Vladislav E. Bougrov, Muhammad Ali, Olli Svensk
Publikováno v:
Semiconductor Science and Technology. 27:082002
We present near-UV GaN light-emitting diodes (LEDs) grown on patterned GaN/sapphire templates with improved material quality and light extraction efficiency. Enhancement of light extraction efficiency is attributed to voids generated at the GaN/sapph
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::48b35249a2f39587002e1a479de25e39
https://doi.org/10.1088/0268-1242/27/8/082002
https://doi.org/10.1088/0268-1242/27/8/082002