1.2 Assembly of Nanowires for Flexible and 3D
High-Performance Nanoelectronics
A wide range of semiconductor nanowires have been produced via CVD growth with
high carrier mobility, including Ge/Si core-shell nanowires (ca. 730 cm^2 V−^1 s−^1 )
[ 45 ], GaAs nanowires (ca. 4100 cm^2 V−^1 s−^1 )[ 56 ] and InAs nanowires (ca.
2000 cm^2 V−^1 s−^1 )[ 57 ] yet assemble individual wires into integrated device is
challenge. Several assembly methods such asflow-directed alignment [ 58 , 59 ],
blown-bubble technique [ 60 ], Langmuir-Blodgett approaches [ 30 , 61 , 62 ] and
shear-printing methods [ 63 – 65 ] have been developed to form large-scale oriented
nanowire arrays at room temperature on virtually all kinds of substrates, including
silicon wafer, glass, plastics, paper, etc. With standard lithography, nanoelectronic
units can be coated with a dielectric layer and connected by metal wires to form
electronic circuitry on those substrates [ 47 ].
Among the different patterning methods, shear-printing methods, especially the
lubricant-assisted contact printing method [ 64 ], show great promise due to their
ability to assemble nanowires uniformly on large scales (several centimeters) and
create high-density individually connected nanowire arrays at high efficiency and
with high alignment ratios (ca. 90–95% at a±5° misalignment angle) (Fig.1.1a).
This process uses the nanowire growth substrate as a donor substrate to direc-
tionally slide over a receiver substrate, which is pre-treated to affiliate with the
Fig. 1.1 Contact printing nanowire for assembly.aSchematics of contact printing nanowire by
lubricant-assisted process Reprinted with permission from Ref. [ 63 ]. Copyright 2008 American
Chemical Society.bSchematics and SEM image of contact printing nanowire by deterministic
nanocombing Reprinted with permission from Ref. [ 69 ]. Copyright 2013 Nature Publishing
Group.
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