skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Nanowire Radial Heterostructures as High Electron Mobility Transistors

Abstract

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{sup 2}/Vs and 21,000 cm{sup 2}/Vs at room temperature and 5 K, respectively, for the heterostructure. Field-effect transistors fabricated with ZrO{sub 2} dielectrics and metal top gates showed excellent gate coupling with near ideal subthreshold slopes of 68 mV/dec, an on/off current ratio of 10{sup 7}, 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 andmore » provides a new platform to study the physics of low-dimensional electron gases.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [2];  [1]
  1. Harvard University
  2. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shared Research Equipment Collaborative Research Center
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1003393
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nano Letters; Journal Volume: 6; Journal Issue: 7
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHEMICAL VAPOR DEPOSITION; DESIGN; DIELECTRIC MATERIALS; ELECTRON GAS; ELECTRON MOBILITY; ELECTRONS; ELONGATION; GASES; IMPLEMENTATION; MONOCRYSTALS; PHYSICS; SYNTHESIS; TRANSISTORS; TRANSMISSION ELECTRON MICROSCOPY; TRANSPORT

Citation Formats

Li, Yat, Xiang, Jie, Qian, Fang, Gradecak, Silvija, Wu, Yue, Yan, Hao, Blom, Douglas Allen, and Lieber, Charles M. Nanowire Radial Heterostructures as High Electron Mobility Transistors. United States: N. p., 2006. Web. doi:10.1021/nl060849z.
Li, Yat, Xiang, Jie, Qian, Fang, Gradecak, Silvija, Wu, Yue, Yan, Hao, Blom, Douglas Allen, & Lieber, Charles M. Nanowire Radial Heterostructures as High Electron Mobility Transistors. United States. doi:10.1021/nl060849z.
Li, Yat, Xiang, Jie, Qian, Fang, Gradecak, Silvija, Wu, Yue, Yan, Hao, Blom, Douglas Allen, and Lieber, Charles M. Sun . "Nanowire Radial Heterostructures as High Electron Mobility Transistors". United States. doi:10.1021/nl060849z.
@article{osti_1003393,
title = {Nanowire Radial Heterostructures as High Electron Mobility Transistors},
author = {Li, Yat and Xiang, Jie and Qian, Fang and Gradecak, Silvija and Wu, Yue and Yan, Hao and Blom, Douglas Allen and Lieber, Charles M.},
abstractNote = {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{sup 2}/Vs and 21,000 cm{sup 2}/Vs at room temperature and 5 K, respectively, for the heterostructure. Field-effect transistors fabricated with ZrO{sub 2} dielectrics and metal top gates showed excellent gate coupling with near ideal subthreshold slopes of 68 mV/dec, an on/off current ratio of 10{sup 7}, 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.},
doi = {10.1021/nl060849z},
journal = {Nano Letters},
number = 7,
volume = 6,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}