Publications
Publication List [Google Scholar Profile]
23. Steve Rebello, Takeki Itoh, Sriram Krishnamoorthy and James S. Speck, Heated H3PO4 etching of (001) β-Ga2O3u , Appl. Phys. Lett. 125, 012102 (2024). [Link]
22. Fikadu Alema, Takeki Itoh, William Brand, Andrei Osinsky and James S. Speck, Controllable nitrogen doping of MOCVD Ga2O3 using NH3, Appl. Phys. Lett. 122, 252105 (2023). [Link]
21. Takeki Itoh*, Fikadu Alema*, William Brand, Marko Tadjer, Andrei Osinsky and James S. Speck, N2O grown high Al composition nitrogen doped β-(AlGa)2O3/β-Ga2O3 using MOCVD, J. Vac. Sci. Technol. A. 41, 042709 (2023). (*: Equal contribution) [Link]
20. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, Continuous Si doping β-Ga2O3 films by plasma-assisted molecular beam epitaxy, APL Mater. 11, 041108 (2023). [Link]
19. [Featured/Cover] Arkka Bhattacharyya, Carl Peterson, Takeki Itoh, Saurav Roy, Jacqueline Cooke, Steve Rebollo, Praneeth Ranga, Berardi-Sensale-Rodriguez and Sriram Krishnamoorthy, Enhancing the electron mobility in Si-doped (010) β-Ga2O3 films with low-temperature buffer layers, APL Mater. 11, 021110 (2020). [Link][Cover]
18. [Editor's pick] Esmat Farzana, Arkka Bhattacharyya, Nolan S Hendricks, Takeki Itoh, Sriram Krishnamoorthy and James S. Speck, Oxidized metal Schottky contact with high-κ dielectric field plate for low-loss high-power vertical β-Ga2O3 Schottky diodes, APL Mater. 10, 111104 (2020). [Link]
17. Akhil Mauze, Takeki Itoh, Yuewei Zhang, Evelyn Deagueros, Feng Wu and James S. Speck, Coherently strained (001) β-(AlxGa1−x)2O3 thin films on β-Ga2O3: Growth and compositional analysis, J. Appl. Phys. 132, 115302 (2022). [Link]
16. Fikadu Alema, Takeki Itoh, Samuel Vogt, James S. Speck and Andrei Osinsky, Highly conductive epitaxial β-Ga2O3 and β-(AlxGa1-x)2O3 films by MOCVD, Jpn. J. Appl. Phys. 61, 100903 (2022). [Link]
15. Kenny Huynh, Michael E Liao, Akhil Mauze, Takeki Itoh, Xingxu Yan, James S Speck, Xiaoqing Pan and Mark S Goorsky, Surface reaction dependence of molecular beam epitaxy grown aluminum on various orientations of β-Ga2O3, APL Mater. 10, 011110 (2022). [Link]
14. Akhil Mauze, Yuewei Zhang, Takeki Itoh and James S. Speck, Mg doping and diffusion in (010) β-Ga2O3 films grown by plasma-assisted molecular beam epitaxy, J. Appl. Phys. 130, 235301 (2021). [Link]
13. Esmat Farzana, Fikadu Alema, Wan Ying Ho, Akhil Mauze, Takeki Itoh, Andrei Osinsky and James S. Speck, Vertical β-Ga2O3 field plate Schottky barrier diode from metal-organic chemical vapor deposition, Appl. Phys. Lett. 118, 162109 (2021). [Link]
12. Robert H. Montgomery, Yuewei Zhang, Chao Yuan, Samuel Kim, Jingjing Shi, Takeki Itoh, Akhil Mauze, Satish Kumar, James S. Speck and Samuel Graham, Thermal management strategies for gallium oxide vertical trench-fin MOSFETs, J. Appl. Phys. 129, 085301 (2021). [Link]
11. Yuewei Zhang, Akhil Mauze, Fikadu Alema, Andrei Osinsky, Takeki Itoh and James S. Speck, β-Ga2O3 lateral transistors with high aspect ratio fin-shape channels, Jpn. J. Appl. Phys. 60, 014001 (2021). [Link]
10. Akhil Mauze, Yuewei Zhang, Takeki Itoh, Elaheh Ahmadi and James S. Speck, Sn doping of (010) β-Ga2O3 films grown by plasma-assisted molecular beam epitaxy, Appl. Phys. Lett. 117, 222102 (2020). [Link]
9. [Editor's picks] Esmat Farzana, Jianfeng Wang, Morteza Monavarian, Takeki Itoh, Kai Shek Qwah, Zachary J Biegler, Kelsey F Jorgensen and James S. Speck, Over 1 kV Vertical GaN-on-GaN pn Diodes with Low On-Resistance using Ammonia Molecular Beam Epitaxy, IEEE Electron Device Lett. 41, 1806 (2020). [Link]
8. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, Epitaxial growth of β-Ga2O3 on (110) substrate by plasma-assisted molecular beam epitaxy, Appl. Phys. Lett. 117, 152105 (2020). [Link]
7. Fikadu Alema, Yuewei Zhang, Akhil Mauze, Takeki Itoh, James S. Speck, Brian Hertog, and Andrei Osinsky, H2O vapor assisted growth of β-Ga2O3 by MOCVD, AIP Advances 10, 085002 (2020). [Link]
6. Chao Yuan, Yuewei Zhang, Robert Montgomery, Samuel Kim, Jingjing Shi, Akhil Mauze, Takeki Itoh, James S. Speck and Samuel Graham, Modeling and analysis for thermal management in gallium oxide field-effect transistors, J. Appl. Phys. 127, 154502 (2020). [Link]
5. [Featured] Akhil Mauze, Yuewei Zhang, Takeki Itoh, Feng Wu and James S. Speck, Metal oxide catalyzed epitaxy (MOCATAXY) of β-Ga2O3 films in various orientations grown by plasma-assisted molecular beam epitaxy, APL Mater. 8, 021104 (2020). [Link]
4. [Featured] Fikadu Alema, Yuewei Zhang, Andrei Osinsky, Nicholas Valente, Akhil Mauze, Takeki Itoh and James S. Speck, Low temperature electron mobility exceeding 104 cm2/V s in MOCVD grown β-Ga2O3, APL Mater. 7, 121110 (2019). [Link]
3. Takeki Itoh, Atsushi Kobayashi, Jitsuo Ohta and Hiroshi Fujioka, High-current-density indium nitride ultrathin-film transistors on glass substrates, Appl. Phys. Lett. 109, 142104 (2016). [Link]
2. Takeki Itoh, Atsushi Kobayashi, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, Fabrication of InGaN thin-film transistors using pulsed sputtering deposition, Sci. Rep. 6, 29500 (2016). [Link]
1. Atsushi Kobayashi, Takeki Itoh, Jitsuo Ohta, Masaharu Oshima and Hiroshi Fujioka, Solid-phase epitaxy of InOxNy alloys via thermal oxidation of InN films on yttria-stabilized zirconia, Phys. Status. Solidi RRL 8, 362-336 (2014). [Link]
Conference Presentations
29. [Invited] Takeki Itoh, Fikadu Alema, Will Brand, James S. Speck and Andrei Osinsky, MOCVD growth of β-(AlGa)2O3 on β-Ga2O3 using N2O, SPIE photonic west 12422- 78 February-2023.
28. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, Continuous Si doping in (010) and (001) β-Ga2O3 films by plasma-assisted molecular beam epitaxy, The 4th International Workshop on Gallium Oxide and Related Materials, Epi 1-4, Nagano, Japan, October-2022.
27. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, β-Ga2O3 epitaxial growth on (110) substrate by plasma-assisted molecular beam epitaxy, The 4th International Workshop on Gallium Oxide and Related Materials, Epi 3-1, Nagano, Japan, October-2022.
26. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, (110) β-Ga2O3 Epitaxial Films Grown by Plasma-Assisted Molecular Beam Epitaxy, 5th Gallium Oxide Workshop, EG-TuA01, Washington, D.C., August-2022.
25. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, Epitaxial Growth on β-Ga2O3 (110) Substrate by Plasma-Assisted Molecular Beam Epitaxy, 64th Electronic Materials Conference, L01, The Ohio State University, July-2022.
24. Takeki Itoh, Akhil Mauze, Yuewei Zhang and James S. Speck, Crystal growth on (110) β-Ga2O3 via plasma-assisted molecular beam epitaxy, SPIE photonic west opto, 116870U, March-2021.
23. Takeki Itoh, Atsushi Kobayashi, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, InGaN thin-film transistors on amorphous glass substrates, The 6th International Symposium on Growth of III-Nitrides, We-B62, Hamamatsu, November-2015.
22. Takeki Itoh, Atsushi Kobayashi, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, Characteristics of thin-film transistors based on nitride semiconductors grown on glass substrates, 76th JSAP Fall Meeting,15a-1D-7, Nagoya Congress Center, September-2015.
21. Takeki Itoh, Atsushi Kobayashi, Jitsuo Ohta, Masaharu Oshima and Hiroshi Fujioka, High mobility c-axis-oriented ultrathin InN films grown on amorphous substrates, 10th International Conference on Nitride Semiconductors, Washington, D.C., August- 2013.
20. Takeki Itoh, Atsushi Kobayashi, Jitsuo Ohta, Masaharu Oshima and Hiroshi Fujioka, Characterization of InN films grown on fused silica, 5th Nitride Semiconductor Crystal Growth Meeting, FR22, Osaka University, June-2013.
19. Takeki Itoh, Atsushi Kobayashi, Jitsuo Ohta, Hiroshi Fujioka and Masaharu Oshima, Characterization of InN films grown on amorphous substrates, 60th JSAP Spring Meeting, 28p-G21-2, Kanagawa Institute of Technology, March-2013.
18. Akhil Mauze, Takeki Itoh, Yuewei Zhang and James S. Speck, Coherently strained (001) β-Ga2O3-(AlxGa1-x)2O3 thin films on β-Ga2O3, The 4th International Workshop on Gallium Oxide and Related Materials, Epi 3-4, Nagano, Japan, October-2022.
17. Akhil Mauze, Takeki Itoh, Yuewei Zhang and James S. Speck, Doping and diffusion of Mg in (010) β-Ga2O3 films grown by plasma-assisted molecular beam epitaxy, The 4th International Workshop on Gallium Oxide and Related Materials, Epi 3-4, Nagano, Japan, October-2022.
16. Fikadu Alema, Takeki Itoh, James S. Speck and Andrei Osinsky, Highly Conductive β-Ga2O3 and (AlxGa1-x)2O3 epitaxial films by MOCVD, 5th Gallium Oxide Workshop, EG-TuP09, Washington, D.C., August-2022.
15. [Invited] Akhil Mauze, Takeki Itoh, Esmat Farzana, Yuewei Zhang and James S. Speck, Materials development for high voltage vertical gallium oxide devices, SPIE photonic west 12422-19 February-2023.
14. Esmat Farzana, Arkka Bhattacharyya, Nolan Hendricks, Takeki Itoh, Sriram Krishnamoorthy and James S. Speck, Metal Oxide (PtOx) Schottky Contact with High-k Dielectric Field Plate for Improved Field management in Vertical β-Ga2O3 Devices, DI-TuA13, Washington, D.C., August-2022.
13. [Invited] Akhil Mauze, Takeki Itoh, Esmat Farzana, Yuewei Zhang and James S. Speck, β-Ga2O3: Growth, Doping, and Device Design, IWUMD 04_1009, May 2022.
12. Esmat Farzana, Fikadu Alema, Takeki Itoh, Nolan Hendricks, Akhil Mauze, Andrei Osinsky and James S. Speck, β-Ga2O3 epitaxy and power devices from metal-organic chemical vapor deposition, SPIE photonic west opto, PC120020H, March-2022.
11. [Invited] Esmat Farzana, Jianfeng Wang, Kelsey Jorgensen, Kai Shek Qwah, Morteza Monavarian, Takeki Itoh, Zachary J Biegler, James S Speck, Vertical GaN Devices for High-Power Electronics, ECS Meeting, H3-1004, October-2021.
10. Jingjing Shi, Anusha Krishnan, A.F.M. Anhar Uddin Bhuiyan, Yee Rui Koh, Kenny Huynh, Akhil Mauze, Sai Mu, Brian M. Foley, Habib Ahmad, Takeki Itoh, Yuewei Zhang, Chao Yuan, Samuel Kim, W. Alan Doolittle, Chirs Van De Walle, James S. Speck, Mark Goorsky, Patrick Hopkins, Hongping Zhao, Samuel Graham, Thermal Transport Across Al-(AlxGa1-x)2O3 and Al-Ga2O3 Interfaces, InterPack, 74116, October-2021.
9. [Invited] Akhil Mauze, Takei Itoh, Esmat Frazana and James S. Speck, Materials progress for the development of β-Ga2O3 for power electronics, Compound Semiconductor Week , May-2021
8. Akhil Mauze, Takeki Itoh, Yuewei Zhang and James S. Speck, Sn doping of (010) β-Ga2O3 films grown by plasma-assisted molecular beam epitaxy, SPIE photonic west opto, 116870I, March-2021.
7. Esmat Farzana, Fikadu Alema, Wan Ying Ho, Takeki Itoh, Andrei Osinsky and James S. Speck, Vertical β-Ga2O3 Schottky diodes from metal-organic chemical vapor deposition with low on-resistance and high average breakdown field, SPIE photonic west opto, 116870G, March-2021.
6. Atsushi Kobayashi, Masumi Sakamoto, Kyohei Nakamura, Khe Shin Lye, Takeki Itoh, Kohei Ueno and Hiroshi Fujioka, Crystal growth of InN on amorphous substrates towards the fabrication of high-mobility thin-film transistors, JSPS 162 committee 110th meeting/special symposium, 6, The University of Tokyo, September-2018.
5. Kyohei Nakmura, Atsushi Kobayashi, Takeki Itoh, Khe Shin Lye, Mari Morita, Kohei Ueno, Jitsuo Ohta, Yuki Tokumoto and Hiroshi Fujioka, Fabrication of thin-film transistors based on InGaN film grown at room temperature, 64th JSAP Spring Meeting, 14a-503-5, Pacifico Yokohama, March-2017.
4. Atsushi Kobayashi, Takeki Itoh, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, Growth of nitride semiconductors on glass substrates and its application for thin-film transistors, 8th Nitride Semiconductor Crystal Growth Meeting, Mo-19, Kyoto University, May-2016.
3. Atsushi Kobayashi, Takeki Itoh, Khe Shin Lye, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, Characterization of InGaN thin-film transistors fabricated on amorphous substrates, 63th JSAP Spring Meeting, 21a-H121-9, Tokyo Institute of Technology, March-2016.
2. Khe Shin Lye, Takeki Itoh, Atsushi Kobayashi, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, Room temperature preparation of InN films on polymer substrates by PSD and its application for TFTs, The 6th International Symposium on Growth of III-Nitrides, We-B57, Hamamatsu, November-2015.
1. Khe Shin Lye, Takeki Itoh, Atsushi Kobayashi, Kohei Ueno, Jitsuo Ohta and Hiroshi Fujioka, Thin-film transistors based on InN grown on polymer sheets at room temperature, 76th JSAP Fall Meeting,15a-1D-8, Nagoya Congress Center, September-2015.