Browsing by Author "Thi-Hien Do"

Now showing 1 - 2 of 2

The Influence of AlN Nucleation Layer on Radio Frequency Transmission Loss of AlN-on-Si Heterostructure
(1970-01-01)
Chang, Shane
;
Zhao, Ming
;
Spampinato, Valentina
;
Franquet, Alexis
;
Thi-Hien Do
Reducing radio frequency (RF) transmission loss is a key requirement when fabricating GaN-on-Si RF devices. To get a better insight into the RF loss mechanism in the GaN-on-Si structure, the RF loss of an AlN/Si template is investigated by varying the growth temperature of AlN during a metalorganic chemical vapor deposition process. The results show that the RF loss of the AlN/Si template is dominated by the interface loss due to the p-type conductive channel at the AlN/Si interface, which is induced by the thermal diffusion of Al during the high-temperature growth. Although a low growth temperature of the AlN nucleation layer can suppress the RF loss in the AlN/Si template, it results in a low crystalline quality of AlN for practical use. Optimizing the growth temperature of the AlN nucleation layer is essential to obtain a good balance between the crystalline quality, morphological quality, and RF loss such that the AlN/Si template is suitable for epitaxial growth of the complete GaN-on-Si RF device structure.
Van der Waals heteroepitaxial AZO/NiO/AZO/muscovite (ANA/muscovite) transparent flexible memristor
(2019-02-01)
Van-Qui Le
;
Thi-Hien Do
;
Retamal, Jose Ramon Duran
;
Shao, Pao-Wen
;
Lai, Yu-Hong
Multifunctional electronics featuring optical transparency, portability, mechanical flexibility, light-weight and environment-friendly are of great demands for next-generation smart electronics. Memristor represents one of the important chains in next-generation devices as the information computing and storage component. Here, we design the transparent flexible structure based on van der Waals heteroepitaxial AZO/NiO/AZO/muscovite (ANA/muscovite) for a memristor application. The (ANA/muscovite) memristor satisfies all the hardest requirements of a transparent soft device such as optical transparency over 80% in visible light and high performance with a ON/OFF resistance ratio > 10(5), stable endurance to 10(3) cycles and long retention time of 10(5) s. In addition, the ANA/muscovite memristor can work at various bending radii down to 5 mm, a mechanical bending after 1000 cycles at a curvature with a radius of 6.5 mm and a high temperature up to 185 degrees C, which deliver a pathway for future applications in flexible transparent smart electronics.