PEER REVIEWED

Under review

  • Tran D., Carrascon R., Sukkaew P., Iwaya M., Monemar B., Darakchieva V., and Paskov P., Thermal conductivity of Al x Ga 1−x N (0≤x≤ 1) epitaxial layers Phys. Rev. Materials.

Published

  1. Kühne P., Armakavicius N., Papamichail A., Tran D., Stanishev V., Schubert M., Paskov P., and Darakchieva V., Enhancement of 2DEG effective mass in AlN/Al0.78Ga0.22N high electron mobility transistor structure determined by THz optical Hall effect, Appl. Phys. Lett. 120, 253102 (2022); https://doi.org/10.1063/5.0087033
  2. Gogova D., Ghezellou M., Tran D., Richter S., Papamichail A., ul-Hassan J., Persson A., Persson P., Kordina O., Monemar B., Hilfiker M., Schubert M., Paskov P., Darakchieva V., Epitaxial growth of β-Ga2O3 by hot-wall MOCVD, AIP Advances 12 055022 (2022); https://doi.org/10.1063/5.0087571
  3. Schubert M., Knight S., Richter S., Kühne P., Stanishev V., Ruder A., Stokey M., Korlacki R., Irmscher K., Neugebauer P., Darakchieva V., Terahertz electron paramagnetic resonance generalized spectroscopic ellipsometry: The magnetic response of the nitrogen defect in 4H-SiC, Appl. Phys. Lett. 120, 102101 (2022); https://doi.org/10.1063/5.0082353
  4. Stokey M., Korlacki R., Knight S., Ruder A., Hilfiker M., Galazka Z., Irmscher K., Zhang Y., Zhao H., Darakchieva V. and Schubert M., Optical phonon modes, static and high frequency dielectric constants, and effective electron mass parameter in cubic In2O3, J. Appl. Phys. 129, 225102 (2021), https://doi.org/10.1063/5.0052848
  5. Tran D. Q., Carrascon R. D., Muth J. F., Paskova T., Nawaz M., Darakchieva V., Paskov P.P., Erratum “Boundary scattering and phonon transport in AlGaN: Effect of layer thickness” [Appl. Phys. Lett. 117, 252102 (2020)], Appl. Phys. Lett. 118, 189901 (2021), https://doi.org/10.1063/5.0054625
  6. Korlacki R., Knudtson J., Stokey M., Hilfiker M., Darakchieva V., and Schubert M., Linear strain and stress potential parameters for the three fundamental band to band transitions in β-Ga2O3, Appl. Phys. Lett. 120, 042103 (2022); https://doi.org/10.1063/5.0078157
  7. Stokey M., Korlacki R., Hilfiker M., Knight S., Richter S., Darakchieva V., Jinno R., Cho Y., Xing H., Jena D., Oshima Y., Khan K., Ahmadi E., and Schubert M., Infrared dielectric functions and Brillouin zone center phonons of α−Ga2O3 compared to α-Al2O3, Phys. Rev. Materials 6, 014601 (2022), https://doi.org/10.1103/PhysRevMaterials.6.014601
  8. Chen D.-Y., Persson A., Wen K.-H., Sommer D., Grünenpütt J., Blanck H., Thorsell M., Kordina O., Darakchieva V., Persson P., Chen J.-T., and Rorsman N., Impact of in situ NH3 pre-treatment of LPCVD SiN passivation on GaN HEMT performance, Semicond. Sci. Technol. 37, 035011 (2022). https://doi.org/10.1088/1361-6641/ac4b17
  9. Zhang H., Persson I., Papamichail A., Chen, J.-T, Persson P., Paskov P., and Darakchieva V., On the polarity determination and polarity inversion in nitrogen-polar group III-nitride layers grown on SiC, Journal of Applied Physics 131, 055701 (2022); https://doi.org/10.1063/5.0074010
  10. H.-Y. Lee, T.-W. Chang, E. Y. Chang, N. Rorsman und C.-T. Lee, Fabrication and Characterization of GaN-Based Fin-Channel Array MetalOxide-Semiconductor High-Electron Mobility Transistors With Recessed Gate and Ga2O3 Gate Insulator Layer, IEEE Journal of the Electron Devices Society 9, 393 (2021). URL https://doi.org/10.1109/JEDS.2021.3069973
  11. J.-J. Jian, H.-Y. Lee, E. Y. Chang, N. Rorsman und C.-T. Lee, Investigation of Multiple-Mesa-Nanochannel Array GaN-Based MOSHEMTs with Al2O3 Gate Dielectric Layer, ECS Journal of Solid State Science and Technology 10 (5), 055017 (2021). URL https://doi.org/10.1149/ 2162-8777/ac029f
  12. R. D. Carrascon, D. Q. Tran, P. Sukkaew, A. Mock, R. Ciechonski, J. Ohlsson, Y. Zhu, O. Hultin, B. Monemar, P. P. Paskov, L. Samuelson und V. Darakchieva, Optimization of GaN Nanowires Reformation Process by Metalorganic Chemical Vapor Deposition for Device-Quality GaN Templates, physica status solidi (b) 257 (4), 1900581 (2020). URL https://doi.org/10.1002/pssb.201900581
  13. D.-Y. Chen, A. Malmros, M. Thorsell, H. Hjelmgren, O. Kordina, J.-T. Chen und N. Rorsman, Microwave Performance of ‘Buffer-Free’ GaNon-SiC High Electron Mobility Transistors, IEEE Electron Device Letters 41 (6), 828 (2020). URL https://doi.org/10.1109/led.2020. 2988074
  14. J. Bremer, D. Y. Chen, A. Malko, M. Madel, N. Rorsman, S. E. Gunnarsson, K. Andersson, T. M. J. Nilsson, P. E. Raad, P. L. Komarov, T. L. Sandy und M. Thorsell, Electric-Based Thermal Characterization of GaN Technologies Affected by Trapping Effects, IEEE Transactions on Electron Devices 67 (5), 1952 (2020). URL https: //doi.org/10.1109/ted.2020.2983277
  15. T. Huang, O. Axelsson, J. Bergsten, M. Thorsell und N. Rorsman, Impact of AlGaN/GaN Interface and Passivation on the Robustness of Low-Noise Amplifiers, IEEE Transactions on Electron Devices 67 (6), 2297 (2020). URL https://doi.org/10.1109/ted.2020.2986806
  16. M. Schubert, A. Mock, R. Korlacki, S. Knight, B. Monemar, K. Goto, Y. Kumagai, A. Kuramata, Z. Galazka, G. Wagner, M. J. Tadjer, V. D. Wheeler, M. Higashiwaki und V. Darakchieva, Phonon Properties, in Gallium Oxide, Springer International Publishing, 501–534 (2020). URL https://doi.org/10.1007/978-3-030-37153-1_28
  17. M. Stokey, A. Mock, R. Korlacki, S. Knight, V. Darakchieva, S. Schöche und M. Schubert, Infrared active phonons in monoclinic lutetium oxyorthosilicate, Journal of Applied Physics 127 (11), 115702 (2020). URL https://doi.org/10.1063/1.5135016
  18. D. Q. Tran, N. Blumenschein, A. Mock, P. Sukkaew, H. Zhang, J. F. Muth, T. Paskova, P. P. Paskov und V. Darakchieva, Thermal conductivity of ultra-wide bandgap thin layers – High Al-content AlGaN and β-Ga2O3, Physica B: Condensed Matter 579, 411810 (2020). URL https://doi.org/10.1016/j.physb.2019.411810
  19. R. Korlacki, A. Mock, C. Briley, V. Darakchieva, B. Monemar, Y. Kumagai, K. Goto, M. Higashiwaki und M. Schubert, Comment on “Characteristics of Multi-photon Absorption in a β-Ga2O3 Single Crystal” [J. Phys. Soc. Jpn. 88, 113701 (2019)], Journal of the Physical Society of Japan 89 (3), 036001 (2020). URL https://doi.org/10.7566/jpsj. 89.036001
  20. H. Zhang, P. P. Paskov, O. Kordina, J.-T. Chen und V. Darakchieva, Npolar AlN nucleation layers grown by hot-wall MOCVD on SiC: Effects of substrate orientation on the polarity, surface morphology and crystal quality, Physica B: Condensed Matter 580, 411819 (2020). URL https: //doi.org/10.1016/j.physb.2019.411819
  21. D. Q. Tran, R. Delgado-Carrascon, J. F. Muth, T. Paskova, M. Nawaz, V. Darakchieva und P. P. Paskov, Phonon-boundary scattering and thermal transport in AlxGa1-xN: Effect of layer thickness, Applied Physics Letters 117 (25), 252102 (2020). URL https://doi.org/10.1063/5.0031404
  22. P. Gopalan, S. Knight, A. Chanana, M. Stokey, P. Ranga, M. A. Scarpulla, S. Krishnamoorthy, V. Darakchieva, Z. Galazka, K. Irmscher, A. Fiedler, S. Blair, M. Schubert und B. Sensale-Rodriguez, The anisotropic quasi-static permittivity of single-crystal β-Ga2O3 measured by terahertz spectroscopy, Applied Physics Letters 117 (25), 252103 (2020). URL https://doi.org/10.1063/5.0031464
  23. R. Korlacki, M. Stokey, A. Mock, S. Knight, A. Papamichail, V. Darakchieva und M. Schubert, Strain and stress relationships for optical phonon modes in monoclinic crystals with β-Ga2O3 as an example, Physical Review B 102 (18) (2020). URL https://doi.org/10. 1103/physrevb.102.180101
  24. S. Knight, S. Schöche, P. Kühne, T. Hofmann, V. Darakchieva und M. Schubert, Tunable cavity-enhanced terahertz frequency-domain optical Hall effect, Review of Scientific Instruments 91 (8), 083903 (2020). URL https://doi.org/10.1063/5.0010267
  25. M. Stokey, R. Korlacki, S. Knight, M. Hilfiker, Z. Galazka, K. Irmscher, V. Darakchieva und M. Schubert, Brillouin zone center phonon modes in ZnGa2O4, Applied Physics Letters 117 (5), 052104 (2020). URL https://doi.org/10.1063/5.0012526
  26. J. Lu, J.-T. Chen, M. Dahlqvist, R. Kabouche, F. Medjdoub, J. Rosen, O. Kordina und L. Hultman, Transmorphic epitaxial growth of AlN nucleation layers on SiC substrates for high-breakdown thin GaN transistors, Applied Physics Letters 115 (22), 221601 (2019). URL https: //doi.org/10.1063/1.5123374
  27. T. Huang, S. An, J. Bergsten, S. He und N. Rorsman, A power detector based on GaN high-electron-mobility transistors for a gigabit on–off keying demodulator at 90 GHz, Japanese Journal of Applied Physics 58 (SC), SCCD19 (2019). URL https://doi.org/10.7567/ 1347-4065/ab09d9
  28. M. Hilfiker, U. Kilic, A. Mock, V. Darakchieva, S. Knight, R. Korlacki, A. Mauze, Y. Zhang, J. Speck und M. Schubert, Dielectric function tensor (1.5 eV to 9.0 eV), anisotropy, and band to band transitions of monoclinic β-(AlxGa1–x)2O3 (x 0.21) films, Applied Physics Letters 114 (23), 231901 (2019). URL https://doi.org/10.1063/1.5097780
  29. A. Malmros, P. Gamarra, M. Thorsell, H. Hjelmgren, C. Lacam, S. L. Delage, H. Zirath und N. Rorsman, Impact of Channel Thickness on the Large-Signal Performance in InAlGaN/AlN/GaN HEMTs With an AlGaN Back Barrier, IEEE Transactions on Electron Devices 66 (1), 364 (2019). URL https://doi.org/10.1109/ted.2018.2881319
  30. A. Malmros, J.-T. Chen, H. Hjelmgren, J. Lu, L. Hultman, O. Kordina, E. O. Sveinbjornsson, H. Zirath und N. Rorsman, Enhanced Mobility in InAlN/AlN/GaN HEMTs Using a GaN Interlayer, IEEE Transactions on Electron Devices 66 (7), 2910 (2019). URL https://doi.org/10. 1109/ted.2019.2914674
  31. M. Schubert, A. Mock, R. Korlacki, S. Knight, Z. Galazka, G. Wagner, V. Wheeler, M. Tadjer, K. Goto und V. Darakchieva, Longitudinal phonon plasmon mode coupling in β-Ga2O3, Applied Physics Letters 114 (10), 102102 (2019). URL https://doi.org/10.1063/1.5089145
  32. M. O. Eriksson, S. Khromov, P. P. Paskov, X. Wang, A. Yoshikawa, P. O. Holtz, B. Monemar und V. Darakchieva, Recombination processes in Mg doped wurtzite InN films with p- and n-type conductivity, AIP Advances 9 (1), 015114 (2019). URL https://doi.org/10.1063/1.5052432
  33. M. Schubert, A. Mock, R. Korlacki und V. Darakchieva, Phonon order and reststrahlen bands of polar vibrations in crystals with monoclinic symmetry, Physical Review B 99 (4) (2019). URL https://doi.org/ 10.1103/physrevb.99.041201
  34. R. Khosa, J. Chen, K. Pàlsson, R. Karhu, J. Hassan, N. Rorsman und E. Sveinbjörnsson, Electrical properties of 4H-SiC MIS capacitors with AlN gate dielectric grown by MOCVD, Solid-State Electronics 153, 52 (2019). URL https://doi.org/10.1016/j.sse.2018.12.016
  35. A. Mock, R. Korlacki, S. Knight, M. Stokey, A. Fritz, V. Darakchieva und M. Schubert, Lattice dynamics of orthorhombic NdGaO3, Physical Review B 99 (18) (2019). URL https://doi.org/10.1103/physrevb. 99.184302
  36. T. Huang, H. Jiang, J. Bergsten, K. M. Lau und N. Rorsman, Enhanced gate stack stability in GaN transistors with gate dielectric of bilayer SiNx by low pressure chemical vapor deposition, Applied Physics Letters 113 (23), 232102 (2018). URL https://doi.org/10.1063/1.5042809
  37. S. Knight, A. Mock, R. Korlacki, V. Darakchieva, B. Monemar, Y. Kumagai, K. Goto, M. Higashiwaki und M. Schubert, Electron effective mass in Sn-doped monoclinic single crystal β-gallium oxide determined by mid-infrared optical Hall effect, Applied Physics Letters 112 (1), 012103 (2018). URL https://doi.org/10.1063/1.5011192
  38. N. Armakavicius, V. Stanishev, S. Knight, P. Kühne, M. Schubert und V. Darakchieva, Electron effective mass in In0.33Ga0.67N determined by mid-infrared optical Hall effect, Applied Physics Letters 112 (8), 082103 (2018). URL https://doi.org/10.1063/1.5018247
  39. P. Kühne, N. Armakavicius, V. Stanishev, C. M. Herzinger, M. Schubert und V. Darakchieva, Advanced Terahertz Frequency-Domain Ellipsometry Instrumentation for In Situ and Ex Situ Applications, IEEE Transactions on Terahertz Science and Technology 8 (3), 257 (2018). URL https://doi.org/10.1109/tthz.2018.2814347
  40. Y.-K. Lin, J. Bergsten, H. Leong, A. Malmros, J.-T. Chen, D.-Y. Chen, O. Kordina, H. Zirath, E. Y. Chang und N. Rorsman, A versatile lowresistance ohmic contact process with ohmic recess and low-temperature annealing for GaN HEMTs, Semiconductor Science and Technology 33 (9), 095019 (2018). URL https://doi.org/10.1088/1361-6641/ aad7a8
  41. J.-T. Chen, J. Bergsten, J. Lu, E. Janzén, M. Thorsell, L. Hultman, N. Rorsman und O. Kordina, A GaN–SiC hybrid material for highfrequency and power electronics, Applied Physics Letters 113 (4), 041605 (2018). URL https://doi.org/10.1063/1.5042049
  42. J. Bremer, J. Bergsten, L. Hanning, T. Nilsson, N. Rorsman, S. Gustafsson, A. M. Eriksson und M. Thorsell, Analysis of Lateral Thermal Coupling for GaN MMIC Technologies, IEEE Transactions on Microwave Theory and Techniques 66 (10), 4430 (2018). URL https://doi.org/10.1109/TMTT.2018.2848932
  43. C. Sánchez-Pérez, C. M. Andersson, K. Buisman, D. Kuylenstierna,N. Rorsman und C. Fager, Design and Large-Signal Characterization of High-Power Varactor-Based Impedance Tuners, IEEE Transactions on Microwave Theory and Techniques 66 (4), 1744 (2018). URL https://doi.org/10.1109/TMTT.2018.2791969
  44. T. Huang, J. Bergsten, M. Thorsell und N. Rorsman, Small- and Large-Signal Analyses of Different Low-Pressure-Chemical-Vapor-Deposition SiNx Passivations for Microwave GaN HEMTs, IEEE Transactions on Electron Devices 65 (3), 908 (2018). URL https://doi.org/10.1109/ TED.2017.2789305
  45. J. Bergsten, M. Thorsell, D. Adolph, J.-T. Chen, O. Kordina, E. O. Sveinbjornsson und N. Rorsman, Electron Trapping in Extended Defects in Microwave AlGaN/GaN HEMTs With Carbon-Doped Buffers, IEEE Transactions on Electron Devices 65 (6), 2446 (2018). URL https://doi.org/10.1109/ted.2018.2828410

DOCTORAL THESIS

LICENTIATE THESES

MASTER THESIS

  • Ohlsson, K. “Optimization of Uniformity in Enhancement of Metal Organic Chemical Vapor Deposition Growth”, Linköping University: Linköping
  • Kai-Hsin Wen, “Study of ohmic contact formation on AlGaN/GaN heterostructures”, Chalmers University of Technology and KTH” http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Akth%3Adiva-259746
  • Oscar Johansson, “Transition Time Impairment of GaN Switches in Electromagnetic Harsh Environments”, Chalmers University of Technology and Saab
  • Emil Bjärehäll, “Power System-on-Chip for Future Airborne Sensor Systems Feasibility Analysis”, Chalmers University of Technology and Saab
  • Laurenz Geihofer, “Epitaxial growth and basic material characterization of β-Ga2O3, Linköping University and Graz University of Technology
  • Yin Zeng, “Characterization and modeling of static and dynamic breakdown characteristics of AlGaN/GaN HEMTs”, Chalmers University of Technology, 2020
  • Kristófer Kristinsson, “GaN FiNFETs”, Chalmers University of Technology, 2021

BACHELOR THESIS

  • Shiqi Guo, “AlGaN/GaN HEMTs with varying Al content barrier layers”, Linköping University: Linköping

CONFERENCE CONTRIBUTIONS

CSW 2022, University of Michigan in Ann Arbor, USA, June 2022

  • A. Papamichail et. al., “Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers”
  • B. Hult et. al., “AlGaN/GaN/AlN ‘Buffer-Free’ High Voltage MISHEMTs with Si-rich and Stoichiometric SiNx First Passivation” (talk)
  • R. Del Castillio et. al., “Considerations in the development of a gate process module for ultra-scaled GaN HEMTs” (poster)
  • M. Mebarki et. al., “GaN HEMT with superconducting Nb gates for low noise cryogenic applications” (talk)

EXMATEC 2021, Bristol, United Kingdom, June 2021 (online)

  • V. Darakchieva et. al., “Terahertz optical Hall effect and Terahertz EPR-ellipsometry of ultrawide bandgap and low-dimensional semiconductor systems” (invited Talk)

International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH), May 2021 (online)

  • D.-Y. Chen et. al., “Thin Al0.5Ga0.5N/GaN HEMTs on QuanFINE® Structure” (Talk)

CSW 2021, Stockholm, Sweden, May 2021 (online)

  • A. Papamichail et. al., “Low Resistivity P-GaN Grown By Hot-wall MOCVD” (Talk)
  • H. Zhang et. al., “Polarity determination and inversion in nitrogen-polar group III-nitride films” (Talk)
  • J. ul Hassan et. al., “CVD Growth and Properties of β-Ga2O3 Epitaxial Layers” (Invited talk)
  • M. Ghezellou et. al. “Hot-Wall MOCVD Epitaxial Growth Of β-Gallium Oxide On Sapphire” (Talk)
  • D. Tran et. al., “Thermal Conductivity Of Wide-bandgap Semiconductors Beyond The Debye Approximation” (Talk)
  • R. Delgado-Carrascon et. al., “Homoepitaxial Growth Of GaN By Hot-wall MOCVD: Thermal Stability And Effect Of H2” (Talk)
  • P. Kühne et. al. “Two-dimensional Electron Gas In AlN/Al0.78Ga0.22N High Electron Mobility Transistor Structure Detected By THz Optical Hall Effect” (Poster)
  • R. Delgado-Carrascon et. al., “Hot-wall MOCVD Growth Of Low Al Content, High Electron Mobility N-type AlxGa1-xN Layers” (Poster)

APWS 2019, Okinawa, Japan, November 2019

  • M. Schubert, A. Mock, R. Korlacki, S. Knight, V. Darakchieva, S. Galazka, G. Wagner, H. Murakami, Y. Kumagai, K. Goto, M. Higashiwaki, and J. Speck. Phonons, free charge carriers, excitons and band-to-band transitions in β-Ga2O3 and related alloys determined by ellipsometry and optical Hall effect (Invited talk)

8th international conference on spectroscopic ellipsometry, ICSE-8, Barcelona, Spain 2019

  • N. Armakavicius, P. Kuehne, V. Stanishev, S. Knight, T. Hofmann, C.M., Herzinger, M. Schubert, and V. Darakchieva “Stealth Technology-Based Terahertz Frequency-Domain Ellipsometry for In-situ and Ex-situ Applications” (Invited talk)
  • P. Kuehne, N. Armakavicius, V. Stanishev, Jr-Tai Chen, O. Kordina, M. Schubert, and V. Darakchieva “Field- and temperature-dependent optical Hall effect in group-III nitrides”(Talk) 
  • A. Mock, R. Korlacki, S. Knight, Z. Galazka, G. Wagner, V. Wheeler, M. Tadjer, K. Goto, and V. Darakchieva M. Schubert “Longitudinal phonon plasmon mode coupling and the strain-stress relationships in β-Ga2O3” (Talk) 
  • A. Mock, R. Korlacki, S. Knight, M. Tadjer, V. Darakchieva, and M. Schubert “Generalized Ellipsometry on Low Symmetry Materials” (Invited talk)

13th International Conference on Nitride Semiconductors, ICNS-13, Bellevue USA,
July 2019

  • D. Y. Chen, Jr. Tai Che, O. Kordina, N. Rorsman, “QuanFINE – High RF Performance AlGaN/AlN/GaN HEMTs with a Thin Buffer Layer”

  • Rosalia Delgado-Carrascon, Dat Tran, Pitsiri Sukkaew, Alyssa Mock, Plamen P. Paskov, Rafal Ciechonski, Jonas Ohlsson, Yadan Zhu, Bo Monemar, Lars Samuelson and Vanya Darakchieva, “High quality GaN templates by coalescence overgrowth of GaN nanowires by MOCVD” (poster)

  • Dat Q. Tran, Pitsiri Sukkaew, Hengfang Zhang, Jr-Tai Chen, Motoaki Iwaya, Isamu Akasaki, Bo Monemar, Vanya Darackchieva, Plamen P. Paskov, “Thermal conductivity of AlGaN layers grown by MOCVD” (poster)

  • Hengfang Zhang, Ingemar Persson, Per Persson, Alyssa Mock, Pitsiri Sukkaew, Jr-Tai Chen and Vanya Darakchieva, “Polarity control in hot-wall MOCVD III-Nitride epitaxy on on-axis and vicinal SiC (000 ̅1) substrates” (poster)

21st International Vacuum Congress IVC-21, Malmö, Sweden, July 2019

  • Rosalia Delgado-Carrascon, Dat Tran, Pitsiri Sukkaew, Alyssa Mock, Plamen P. Paskov, Rafal Ciechonski, Jonas Ohlsson, Yadan Zhu, Bo Monemar, Lars Samuelson and Vanya Darakchieva, “High quality GaN templates by coalescence overgrowth of GaN nanowires by MOCVD” (talk)

  • Hengfang Zhang, Plamen Paskov, Olof Kordina, Jr. Tai Chen, Vanya Darakchieva “N-polar epitaxy of III Nitrides by hot wall MOCVD” (talk)

  • Olof Kordina “QuanFINE as RF and power device material” (invited)

8th South African Conference on Photonic Materials, Kariega, SA, May 2019

  • Kühne, P. Armakavicius, N. Stanishev, V. Chen, J.-T.; Kordina, O. Schubert, M. Darakchieva, V. Free Charge Carrier Properties in Group-III Nitride High Electron Mobility Transistor Structures Determined by Optical Hall Effect; Kariega, South Africa, 2019. Abstract
  • Zhang, H. Persson, I. Persson, P. Mock, A. Sukkaew, P. Chen, J.-T. Darakchieva, V. A Comprehensive Study of AlN Nucleation Layers Grown onto On-Axis and 4° off-Axis SiC (000𝟏̅) Substrates and Its Influence on GaN Growth; Kariega, South Africa, 2019. Abstract
  • Tran, D. Q. Sukkaew, P. Mock, A. Zhang, H. Blumenschein, N. Muth, John F. Paskov, P. P. Darackchieva, V. Thermal Conductivity of Ultra-Wide Bandgap Thin Layers: High-Al Content AlGaN and β-Ga2O3; Kariega, South Africa, 2019. Abstract
  • Darackchieva, V. Free charge carrier properties and phonon-plasmon coupling in ultrawide band gap semiconductors (invited talk); Kariega, South Africa, 2019.

Speck SPIE Opto Photonics West 2019, San Francisco, California, U.S.A., February 2019

  • M. Schubert, A. Mock, R. Korlacki, S. Knight, V. Darakchieva, S. Galazka, G. Wagner, H. Murakami, Y. Kumagai, K. Goto, M. Higashiwaki, and J. Speck. Phonon-plasmon coupling in monoclinic symmetry Ga2O3 (Invited talk)

10th International Workshop on Nitride Semiconductors, IWN2018, Kanazawa, Japan, November 2018

  • Sukkaew, P. Rönnby, K. Chen, J.-T. Zhang, H. Ojamäe, L. Darakchieva, V. Investigation of Growth Mode in AlN Buffer Layer for Strain and Dislocation Control in Al-Rich AlGaN Using Hot-Wall MOCVD; Kanazawa, Japan, 2018. Poster
  • Zhang, H. Persson, I. Persson, P. Mock, A. Sukkaew, P. Chen, J.-T. Darakchieva, V. Comparative Study of GaN Grown on On-Axis and Vicinal SiC (000𝟏̅) Substrates by Hot-Wall MOCVD; Kanazawa, Japan, 2018. Abstract
  • Sukkaew, P. Rönnby, K. Chen, J.-T. Zhang, H. Ojamäe, L. Darakchieva, V. Control of Growth Mode, Dislocations and Strain in Al-Rich AlGaN by Hot-Wall MOCVD; Kanazawa, Japan, 2018. Poster
  • Sukkaew, P. Chen, J.-T. Zhang, H. Darakchieva, V. The Control of Growth Mode and Strain in Al-Rich AlGaN by MOCVD; Kanazawa, Japan, 2019. Abstract

European Microwave week CSW2018, Madrid, Spain, September 2018

  • I. Angelov, “Modeling Semiconductor devices for PA” (Invited talk)

7th International Symposium on Growth of Nitride Semiconductors, ISGN-7, Warsaw, Poland, August 2018

  • Zhang, H. Sukkaew, P. Chen J.-T. and Darakchieva, V. “Hot-wall MOCVD growth of N-polar AlN nucleation layers on C-face vicinal and on-axis SiC substrates” (talk)

GaN Marathon 2.0, Padova, Italy, April 2018

  • Jr. Tai Chen ”A revolutionaryy GaN-on-SiC epitaxy for high frequency power transistors” (Invited talk)

Compound Semiconductor Week CSW2018, MIT, USA, May 2018

  • J. Bergsten et. al., “Influence of Fe- And C-doped Buffers on Microwave Output Power and Dynamic Effects in AlGaN/GaN HEMTs” (Talk)
  • I. Angelov et al. “On the large Signal Modeling of MM wave GaAs PIN diodes” (poster)