Zobrazeno 1 - 10
of 161
pro vyhledávání: '"Vanya Darakchieva"'
Autor:
Nerijus Armakavicius, Sean Knight, Philipp Kühne, Vallery Stanishev, Dat Q. Tran, Steffen Richter, Alexis Papamichail, Megan Stokey, Preston Sorensen, Ufuk Kilic, Mathias Schubert, Plamen P. Paskov, Vanya Darakchieva
Publikováno v:
APL Materials, Vol 12, Iss 2, Pp 021114-021114-8 (2024)
Electron effective mass is a fundamental material parameter defining the free charge carrier transport properties, but it is very challenging to be experimentally determined at high temperatures relevant to device operation. In this work, we obtain t
Externí odkaz:
https://doaj.org/article/a62493e81d3148308344fc53ad392bc7
Autor:
Chaoyang Kuang, Shangzhi Chen, Min Luo, Qilun Zhang, Xiao Sun, Shaobo Han, Qingqing Wang, Vallery Stanishev, Vanya Darakchieva, Reverant Crispin, Mats Fahlman, Dan Zhao, Qiye Wen, Magnus P. Jonsson
Publikováno v:
Advanced Science, Vol 11, Iss 3, Pp n/a-n/a (2024)
Abstract Terahertz (THz) technologies provide opportunities ranging from calibration targets for satellites and telescopes to communication devices and biomedical imaging systems. A main component will be broadband THz absorbers with switchability. H
Externí odkaz:
https://doaj.org/article/b9f1dd52e20c4671b7d641651f9696f9
Autor:
Arnar M. Vidarsson, Axel R. Persson, Jr-Tai Chen, Daniel Haasmann, Jawad Ul Hassan, Sima Dimitrijev, Niklas Rorsman, Vanya Darakchieva, Einar Ö. Sveinbjörnsson
Publikováno v:
APL Materials, Vol 11, Iss 11, Pp 111121-111121-7 (2023)
Very fast interface traps have recently been suggested to be the main cause behind poor channel-carrier mobility in SiC metal–oxide–semiconductor field effect transistors. It has been hypothesized that the NI traps are defects located inside the
Externí odkaz:
https://doaj.org/article/47769d9eaac04af9925d4bf883195c57
Publikováno v:
AIP Advances, Vol 13, Iss 9, Pp 095009-095009-6 (2023)
GaN-based power devices operating at high currents and high voltages are critically affected by the dissipation of Joule heat generated in the active regions. Consequently, knowledge of GaN thermal conductivity is crucial for effective thermal manage
Externí odkaz:
https://doaj.org/article/33d712032bf64cf6b80486fbb2df681a
Publikováno v:
Scientific Reports, Vol 12, Iss 1, Pp 1-10 (2022)
Abstract Structural defects in Mg-doped GaN were analyzed using high-resolution scanning transmission electron microscopy combined with electron energy loss spectroscopy. The defects, in the shape of inverted pyramids, appear at high concentrations o
Externí odkaz:
https://doaj.org/article/adf69f09c2e7437591686a3d9339076c
Autor:
Akchheta Karki, Yu Yamashita, Shangzhi Chen, Tadanori Kurosawa, Jun Takeya, Vallery Stanishev, Vanya Darakchieva, Shun Watanabe, Magnus P. Jonsson
Publikováno v:
Communications Materials, Vol 3, Iss 1, Pp 1-8 (2022)
Optical nanoantennas based on organic plasmonics are promising for their higher degree of tunability over metallic nanostructures. Here, nanodisks of polythiophene-based semiconducting polymers provide nanooptical antennas with resonances that are tu
Externí odkaz:
https://doaj.org/article/83acaeb16ec845bd90aae234943479f6
Autor:
Daniela Gogova, Misagh Ghezellou, Dat Q. Tran, Steffen Richter, Alexis Papamichail, Jawad ul Hassan, Axel R. Persson, Per O. Å. Persson, Olof Kordina, Bo Monemar, Matthew Hilfiker, Mathias Schubert, Plamen P. Paskov, Vanya Darakchieva
Publikováno v:
AIP Advances, Vol 12, Iss 5, Pp 055022-055022-7 (2022)
The hot-wall metalorganic chemical vapor deposition (MOCVD) concept, previously shown to enable superior material quality and high performance devices based on wide bandgap semiconductors, such as Ga(Al)N and SiC, has been applied to the epitaxial gr
Externí odkaz:
https://doaj.org/article/838571abaa974ef99a971173bbe4aea5
Autor:
Ingemar Persson, Nerijus Armakavicius, Chamseddine Bouhafs, Vallery Stanishev, Philipp Kühne, Tino Hofmann, Mathias Schubert, Johanna Rosen, Rositsa Yakimova, Per O. Å. Persson, Vanya Darakchieva
Publikováno v:
APL Materials, Vol 8, Iss 1, Pp 011104-011104-7 (2020)
We study the origin of layer decoupling in ordered multilayer graphene grown by high temperature sublimation on C-face 4H-SiC. The mid-infrared optical Hall effect technique is used to determine the magnetic field dependence of the inter-Landau level
Externí odkaz:
https://doaj.org/article/f36ffb8b212a43388e670b6d34888a94
Autor:
Sean Knight, Tino Hofmann, Chamseddine Bouhafs, Nerijus Armakavicius, Philipp Kühne, Vallery Stanishev, Ivan G. Ivanov, Rositsa Yakimova, Shawn Wimer, Mathias Schubert, Vanya Darakchieva
Publikováno v:
Scientific Reports, Vol 7, Iss 1, Pp 1-8 (2017)
Abstract Unraveling the doping-related charge carrier scattering mechanisms in two-dimensional materials such as graphene is vital for limiting parasitic electrical conductivity losses in future electronic applications. While electric field doping is
Externí odkaz:
https://doaj.org/article/43165a8e218d4f1ea36a7efdb4794529
Autor:
Vallery Stanishev, Nerijus Armakavicius, Chamseddine Bouhafs, Camilla Coletti, Philipp Kühne, Ivan G. Ivanov, Alexei A. Zakharov, Rositsa Yakimova, Vanya Darakchieva
Publikováno v:
Applied Sciences, Vol 11, Iss 4, p 1891 (2021)
In this work we have critically reviewed the processes in high-temperature sublimation growth of graphene in Ar atmosphere using closed graphite crucible. Special focus is put on buffer layer formation and free charge carrier properties of monolayer
Externí odkaz:
https://doaj.org/article/e9658c56484546069bc5ef55d533e08f