Approaching the Hole Mobility Limit of GaSb Nanowires.
In recent years, high-mobility GaSb nanowires have received tremendous attention for high-performance p-type transistors; however, due to the difficulty in achieving thin and uniform nanowires (NWs), there is limited report until now addressing their diameter-dependent properties and their hole mobility limit in this important one-dimensional material system, where all these are essential information for the deployment of GaSb NWs in various applications. Here, by employing the newly developed surfactant-assisted chemical vapor deposition, high-quality and uniform GaSb NWs with controllable diameters, spanning from 16 to 70 nm, are successfully prepared, enabling the direct assessment of their growth orientation and hole mobility as a function of diameter while elucidating the role of sulfur surfactant and the interplay between surface and interface energies of NWs on their electrical properties. The sulfur passivation is found to efficiently stabilize the high-energy NW sidewalls of (111) and (311) in order to yield the thin NWs (i.e., <40 nm in diameters) with the dominant growth orientations of ⟨211⟩ and ⟨110⟩, whereas the thick NWs (i.e., >40 nm in diameters) would grow along the most energy-favorable close-packed planes with the orientation of ⟨111⟩, supported by the approximate atomic models. Importantly, through the reliable control of sulfur passivation, growth orientation and surface roughness, GaSb NWs with the peak hole mobility of ∼400 cm(2)V s(-1) for the diameter of 48 nm, approaching the theoretical limit under the hole concentration of ∼2.2 × 10(18) cm(-3), can be achieved for the first time. All these indicate their promising potency for utilizations in different technological domains.
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|State Key Laboratory of Millimeter Waves, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|Shenzhen Research Institute, City University of Hong Kong , Shenzhen 518057, P. R. China.
Zai-xing
ZX
Yang
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|State Key Laboratory of Millimeter Waves, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|Shenzhen Research Institute, City University of Hong Kong , Shenzhen 518057, P. R. China.
SenPo
S
Yip
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|Shenzhen Research Institute, City University of Hong Kong , Shenzhen 518057, P. R. China.
Dapan
D
Li
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, P. R. China.
Ning
N
Han
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|Shenzhen Research Institute, City University of Hong Kong , Shenzhen 518057, P. R. China.
Guofa
G
Dong
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|Shenzhen Research Institute, City University of Hong Kong , Shenzhen 518057, P. R. China.
Xiaoguang
X
Liang
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.
Lei
L
Shu
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.
Tak Fu
TF
Hung
Department of Materials Science, 220 Handan Road, Fudan University , Shanghai 200433, P. R. China.
Xiaoliang
X
Mo
Department of Physics and Materials Science, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|State Key Laboratory of Millimeter Waves, City University of Hong Kong , 83 Tat Chee Avenue, Kowloon 999077, Hong Kong.|Shenzhen Research Institute, City University of Hong Kong , Shenzhen 518057, P. R. China.
Johnny C
JC
Ho
GaSb nanowires; diameter dependent; growth orientation; hole mobility; surfactant-assisted chemical vapor deposition