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1. GaN-on-GaN p-i-n diodes with avalanche capability enabled by eliminating surface leakage with hydrogen plasma treatment

   https://doi.org/10.1063/5.0107677  

   Fu, Kai ; He, Ziyi ; Yang, Chen ; Zhou, Jingan ; Fu, Houqiang ; Zhao, Yuji ( August 2022 , Applied Physics Letters)

   Traditional mesa terminations require precise angle design to reduce the electric field at the edge and surface treatment to reduce etch damage. Otherwise, the device usually suffers a premature breakdown. This work proposes the use of easy-to-implement hydrogen plasma treatment to solve the premature breakdown caused by mesa and demonstrates the avalanche capability in GaN-on-GaN p-i-n diodes. The breakdown electric field when the avalanche occurred was ∼2.3 MV/cm at room temperature for a GaN drift layer with a doping concentration of ∼7 × 1015 cm−3, which is consistent with the theoretical value. The temperature coefficient of the avalanche breakdown voltage of the devices was 4.64–4.85 × 10−4 K−1. This work shows a simple and effective approach to achieve avalanche capability in vertical GaN power devices, which can serve as an important reference for the future development of efficient and robust GaN power electronics.

    

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2. Structural and optical properties of nonpolar m- and a- plane GaN/AlGaN heterostructures for narrow-linewidth mid-infrared intersubband transitions

   https://doi.org/10.1063/1.5143785  

   Monavarian, Morteza ; Xu, Jiaming ; Fireman, Micha N. ; Nookala, Nishant ; Wu, Feng ; Bonef, Bastien ; Qwah, Kai S. ; Young, Erin C. ; Belkin, Mikhail A. ; Speck, James S. ( May 2020 , Applied Physics Letters)
3. Improvement of optical quality of semipolar (112¯2) GaN on m- plane sapphire by in-situ epitaxial lateral overgrowth

   https://doi.org/10.1063/1.4945770  

   Monavarian, Morteza ; Izyumskaya, Natalia ; Müller, Marcus ; Metzner, Sebastian ; Veit, Peter ; Can, Nuri ; Das, Saikat ; Özgür, Ümit ; Bertram, Frank ; Christen, Jürgen ; et al ( April 2016 , Journal of Applied Physics)
4. Epitaxial Sc x Al 1− x N on GaN exhibits attractive high-K dielectric properties

   https://doi.org/10.1063/5.0075636  

   Casamento, Joseph ; Lee, Hyunjea ; Maeda, Takuya ; Gund, Ved ; Nomoto, Kazuki ; van Deurzen, Len ; Turner, Wesley ; Fay, Patrick ; Mu, Sai ; Van de Walle, Chris G. ; et al ( April 2022 , Applied Physics Letters)

   Epitaxial Sc_xAl_1−xN thin films of ∼100 nm thickness grown on metal polar GaN substrates are found to exhibit significantly enhanced relative dielectric permittivity (ε_r) values relative to AlN. ε_rvalues of ∼17–21 for Sc mole fractions of 17%–25% ( x = 0.17–0.25) measured electrically by capacitance–voltage measurements indicate that Sc_xAl_1−xN has the largest relative dielectric permittivity of any existing nitride material. Since epitaxial Sc_xAl_1−xN layers deposited on GaN also exhibit large polarization discontinuity, the heterojunction can exploit the in situ high-K dielectric property to extend transistor operation for power electronics and high-speed microwave applications.

    

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5. Structure and Interface Analysis of Diamond on an AlGaN/GaN HEMT Utilizing an in Situ SiN x Interlayer Grown by MOCVD

   https://doi.org/10.1021/acsaelm.9b00131  

   Siddique, Anwar ; Ahmed, Raju ; Anderson, Jonathan ; Nazari, Mohammad ; Yates, Luke ; Graham, Samuel ; Holtz, Mark ; Piner, Edwin L. ( July 2019 , ACS Applied Electronic Materials)