Zobrazeno 1 - 10
of 135
pro vyhledávání: '"Leo J. Schowalter"'
Publikováno v:
Gallium Nitride Materials and Devices XVII.
Autor:
Ziyi Zhang, Maki Kushimoto, Akira Yoshikawa, Koji Aoto, Chiaki Sasaoka, Leo J. Schowalter, Hiroshi Amano
Publikováno v:
Applied Physics Letters.
Although the pulsed operation of AlGaN-based laser diodes at UV-C wavelengths has been confirmed in the previous studies, continuous oscillation without cooling is difficult because of the high operating voltage. In this study, the temperature depend
Autor:
Maki Kushimoto, Ziyi Zhang, Akira Yoshikawa, Koji Aoto, Yoshio Honda, Chiaki Sasaoka, Leo J. Schowalter, Hiroshi Amano
Publikováno v:
Applied Physics Letters. 121:222101
Previously reported UV-C laser diode (LD) structures have been subject to design constraints owing to dark line defects at the edge of the mesa stripe after device fabrication. To address this issue, a detailed analysis revealed that the dark line de
Autor:
Chiaki Sasaoka, Maki Kushimoto, Yoshio Honda, Zhang Ziyi, Hiroshi Amano, Naoharu Sugiyama, Leo J. Schowalter
Publikováno v:
Gallium Nitride Materials and Devices XVI.
UV-C laser diodes (LDs) have not been realized for many years owing to the problems of crystal quality and p-type conductivity control. In our group, AlGaN-based LD structures with low dislocation density were fabricated using AlN single-crystal subs
Autor:
Ziyi Zhang, Maki Kushimoto, Akira Yoshikawa, Koji Aoto, Leo J. Schowalter, Chiaki Sasaoka, Hiroshi Amano
Publikováno v:
Applied Physics Express. 15:041007
We demonstrated continuous-wave lasing of an AlGaN-based ultraviolet laser diode, fabricated on a single-crystal AlN substrate when operating at 5 °C. The threshold current density and device series resistance were reduced by improvements to the epi
Autor:
Biplab Sarkar, Ferdinand Scholz, Yuewei Zhang, Friedhard Römer, Hideki Hirayama, Luca Sulmoni, Yukio Kashima, Mitsuru Funato, Ryota Ishii, Robert W. Martin, Philip A. Shields, Akira Hirano, Tim Wernicke, Siddharth Rajan, Michael Kneissl, Yoichi Kawakami, Abdallah Ougazzaden, Peter J. Parbrook, Zlatko Sitar, Pramod Reddy, Ramon Collazo, Matteo Meneghini, Johannes Glaab, Carlo De Santi, Frank Mehnke, Ronny Kirste, Hiroshi Amano, Yuh-Renn Wu, Thomas Wunderer, Tao Wang, Markus Weyers, Sven Einfeldt, Leo J. Schowalter, Jan Ruschel, Bernd Witzigmann, Sylvia Hagedorn
Publikováno v:
Journal of Physics D: Applied Physics
Journal of Physics D: Applied Physics, IOP Publishing, 2020, 53 (50), ⟨10.1088/1361-6463/aba64c⟩
Journal of Physics D: Applied Physics, IOP Publishing, 2020, 53 (50), ⟨10.1088/1361-6463/aba64c⟩
Solid state UV emitters have many advantages over conventional UV sources. The (Al,In,Ga)N material system is best suited to produce LEDs and laser diodes from 400 nm down to 210 nm—due to its large and tuneable direct band gap, n- and p-doping cap
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7c86b3da33184937f47d3f9060fa876c
https://depositonce.tu-berlin.de/handle/11303/16290
https://depositonce.tu-berlin.de/handle/11303/16290
Publikováno v:
Japanese Journal of Applied Physics. 61:010601
The presence of hexagonal-pyramid-shaped hillocks (HPHs) in AlGaN epitaxial films affects device characteristics; this effect is significant in DUV laser diodes (LDs) on AlN substrates, where the presence of HPHs under the p-electrode increases the t
Autor:
Hiroshi Amano, Ziyi Zhang, Leo J. Schowalter, Naoharu Sugiyama, Maki Kushimoto, Yoshio Honda, Chiaki Sasaoka
Publikováno v:
Applied Physics Express. 14:051003
The electroluminescence (EL) uniformity of AlGaN-based deep UV laser diodes on AlN substrate was analyzed by using the EL imaging technique. Although nonuniform EL patterns were observed, the uniformity was improved by changing the position of the p-
Autor:
Masato Toita, Huili Grace Xing, Kevin Lee, Debdeep Jena, Leo J. Schowalter, Ryan Page, Vladimir Protasenko
Publikováno v:
Applied Physics Letters. 118:092101
Single-crystal Aluminum Nitride (AlN) crystals enable the epitaxial growth of ultrawide bandgap Al(Ga)N alloys with drastically lower extended defect densities. Here, we report the plasma-MBE growth conditions for high Al-composition AlGaN alloys on
Autor:
Leo J. Schowalter, Ziyi Zhang, Chiaki Sasaoka, Hiroshi Amano, Masahiro Horita, Naoharu Sugiyama, Maki Kushimoto
Publikováno v:
Applied Physics Letters. 117:152104
The space charge density profile of the nondoped AlGaN-based p-type cladding layer for UV-C laser diodes realized by distributed polarization doping is examined theoretically and experimentally. The analysis of the capacitance-voltage measurement rev