Li, Yat and Xiang, Jie and Qian, Fang and Gradecak, Silvija and Wu, Yue and Yan, Hao and Yan, Hao and Blom, Douglas A. and Lieber, Charles M. (2006) Dopant-free GaN/AlN/AlGaN radial nanowire heterostructures as high electron mobility transistors. NANO LETTERS, 6 (7). pp. 1468-1473.
Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.
Official URL: http://pubs.acs.org/doi/abs/10.1021/nl060849z
We report the rational synthesis of dopant-free GaN/AlN/AlGaN radial nanowire heterostructures and their implementation as high electron mobility transistors (HEMTs). The radial nanowire heterostructures were prepared by sequential shell growth immediately following nanowire elongation using metal-organic chemical vapor deposition (MOCVD). Transmission electron microscopy (TEM) studies reveal that the GaN/AlN/AlGaN radial nanowire heterostructures are dislocation-free single crystals. In addition, the thicknesses and compositions of the individual AlN and AlGaN shells were unambiguously identified using cross-sectional high-angle annular darkfield scanning transmission electron microscopy (HAADF-STEM). Transport measurements carried out on GaN/AlN/AlGaN and GaN nanowires prepared using similar conditions demonstrate the existence of electron gas in the undoped GaN/AlN/AlGaN nanowire heterostructures and also yield an intrinsic electron mobility of 3100 cm(2)/Vs and 21 000 cm(2)/Vs at room temperature and 5 K, respectively, for the heterostructure. Field-effect transistors fabricated with ZrO2 dielectrics and metal top gates showed excellent gate coupling with near ideal subthreshold slopes of 68 mV/dec, an on/off current ratio of 107, and scaled on-current and transconductance values of 500 mA/mm and 420 mS/mm. The ability to control synthetically the electronic properties of nanowires using band structure design in III-nitride radial nanowire heterostructures opens up new opportunities for nanoelectronics and provides a new platform to study the physics of low-dimensional electron gases.
|Subjects:||Physical Science > Nanoelectronics|
|Deposited By:||Lesley Tobin|
|Deposited On:||08 Jan 2009 16:41|
|Last Modified:||08 Jan 2009 16:41|
Repository Staff Only: item control page