<s>
Silicon	B-Algorithm
nanowires	I-Algorithm
,	O
also	O
referred	O
to	O
as	O
SiNWs	B-Algorithm
,	O
are	O
a	O
type	O
of	O
semiconductor	O
nanowire	B-Architecture
most	O
often	O
formed	O
from	O
a	O
silicon	O
precursor	O
by	O
etching	O
of	O
a	O
solid	O
or	O
through	O
catalyzed	O
growth	O
from	O
a	O
vapor	O
or	O
liquid	O
phase	O
.	O
</s>
<s>
Such	O
nanowires	B-Architecture
have	O
promising	O
applications	O
in	O
lithium	B-Language
ion	O
batteries	O
,	O
thermoelectrics	O
and	O
sensors	B-Application
.	O
</s>
<s>
Initial	O
synthesis	O
of	O
SiNWs	B-Algorithm
is	O
often	O
accompanied	O
by	O
thermal	B-Algorithm
oxidation	I-Algorithm
steps	O
to	O
yield	O
structures	O
of	O
accurately	O
tailored	O
size	O
and	O
morphology	O
.	O
</s>
<s>
SiNWs	B-Algorithm
have	O
unique	O
properties	O
that	O
are	O
not	O
seen	O
in	O
bulk	O
(	O
three-dimensional	O
)	O
silicon	O
materials	O
.	O
</s>
<s>
The	O
reason	O
that	O
SiNWs	B-Algorithm
are	O
considered	O
one	O
of	O
the	O
most	O
important	O
one-dimensional	O
materials	O
is	O
they	O
could	O
have	O
a	O
function	O
as	O
building	O
blocks	O
for	O
nanoscale	O
electronics	O
assembled	O
without	O
the	O
need	O
for	O
complex	O
and	O
costly	O
fabrication	O
facilities	O
.	O
</s>
<s>
SiNWs	B-Algorithm
are	O
frequently	O
studied	O
towards	O
applications	O
including	O
photovoltaics	O
,	O
nanowire	B-Algorithm
batteries	I-Algorithm
,	O
thermoelectrics	O
and	O
non-volatile	O
memory	O
.	O
</s>
<s>
Owing	O
to	O
their	O
unique	O
physical	O
and	O
chemical	O
properties	O
,	O
silicon	B-Algorithm
nanowires	I-Algorithm
are	O
a	O
promising	O
candidate	O
for	O
a	O
wide	O
range	O
of	O
applications	O
that	O
draw	O
on	O
their	O
unique	O
physico-chemical	O
characteristics	O
,	O
which	O
differ	O
from	O
those	O
of	O
bulk	O
silicon	O
material	O
.	O
</s>
<s>
SiNWs	B-Algorithm
exhibit	O
charge	O
trapping	O
behavior	O
which	O
renders	O
such	O
systems	O
of	O
value	O
in	O
applications	O
necessitating	O
electron	O
hole	O
separation	O
such	O
as	O
photovoltaics	O
,	O
and	O
photocatalysts	O
.	O
</s>
<s>
Recent	O
experiment	O
on	O
nanowire	B-Architecture
solar	O
cells	O
has	O
led	O
to	O
a	O
remarkable	O
improvement	O
of	O
the	O
power	O
conversion	O
efficiency	O
of	O
SiNW	B-Algorithm
solar	O
cells	O
from	O
<	O
1%	O
to	O
>17	O
%	O
in	O
the	O
last	O
few	O
years	O
.	O
</s>
<s>
Charge	O
trapping	O
behaviour	O
and	O
tuneable	O
surface	O
governed	O
transport	O
properties	O
of	O
SiNWs	B-Algorithm
render	O
this	O
category	O
of	O
nanostructures	O
of	O
interest	O
towards	O
use	O
as	O
metal	O
insulator	O
semiconductors	O
and	O
field	B-Architecture
effect	I-Architecture
transistors	I-Architecture
,	O
with	O
further	O
applications	O
as	O
nanoelectronic	O
storage	O
devices	O
,	O
in	O
flash	B-Device
memory	I-Device
,	O
logic	O
devices	O
as	O
well	O
as	O
chemical	O
and	O
biological	O
sensors	B-Application
.	O
</s>
<s>
The	O
ability	O
for	O
lithium	B-Language
ions	O
to	O
intercalate	O
into	O
silicon	O
structures	O
renders	O
various	O
Si	O
nanostructures	O
of	O
interest	O
towards	O
applications	O
as	O
anodes	O
in	O
Li-ion	O
batteries	O
(	O
LiBs	O
)	O
.	O
</s>
<s>
SiNWs	B-Algorithm
are	O
of	O
particular	O
merit	O
as	O
such	O
anodes	O
as	O
they	O
exhibit	O
the	O
ability	O
to	O
undergo	O
significant	O
lithiation	O
while	O
maintaining	O
structural	O
integrity	O
and	O
electrical	O
connectivity	O
.	O
</s>
<s>
Silicon	B-Algorithm
nanowires	I-Algorithm
are	O
efficient	O
thermoelectric	O
generators	O
because	O
they	O
combine	O
a	O
high	O
electrical	O
conductivity	O
,	O
owing	O
to	O
the	O
bulk	O
properties	O
of	O
doped	O
Si	O
,	O
with	O
low	O
thermal	O
conductivity	O
due	O
to	O
the	O
small	O
cross	O
section	O
.	O
</s>
<s>
Several	O
synthesis	O
methods	O
are	O
known	O
for	O
SiNWs	B-Algorithm
and	O
these	O
can	O
be	O
broadly	O
divided	O
into	O
methods	O
which	O
start	O
with	O
bulk	O
silicon	O
and	O
remove	O
material	O
to	O
yield	O
nanowires	B-Architecture
,	O
also	O
known	O
as	O
top-down	O
synthesis	O
,	O
and	O
methods	O
which	O
use	O
a	O
chemical	O
or	O
vapor	O
precursor	O
to	O
build	O
nanowires	B-Architecture
in	O
a	O
process	O
generally	O
considered	O
to	O
be	O
bottom-up	O
synthesis	O
.	O
</s>
<s>
Vapour	O
liquid	O
solid	O
(	O
VLS	O
)	O
growth	O
–	O
a	O
type	O
of	O
catalysed	O
CVD	B-Algorithm
often	O
using	O
silane	O
as	O
Si	O
precursor	O
and	O
gold	O
nanoparticles	O
as	O
catalyst	O
(	O
or	O
'	O
seed	O
 '	O
)	O
.	O
</s>
<s>
Subsequent	O
to	O
physical	O
or	O
chemical	O
processing	O
,	O
either	O
top-down	O
or	O
bottom-up	O
,	O
to	O
obtain	O
initial	O
silicon	O
nanostructures	O
,	O
thermal	B-Algorithm
oxidation	I-Algorithm
steps	O
are	O
often	O
applied	O
in	O
order	O
to	O
obtain	O
materials	O
with	O
desired	O
size	O
and	O
aspect	B-Device
ratio	I-Device
.	O
</s>
<s>
Silicon	B-Algorithm
nanowires	I-Algorithm
exhibit	O
a	O
distinct	O
and	O
useful	O
self-limiting	O
oxidation	O
behaviour	O
whereby	O
oxidation	O
effectively	O
ceases	O
due	O
to	O
diffusion	O
limitations	O
,	O
which	O
can	O
be	O
modeled	O
.	O
</s>
<s>
This	O
phenomenon	O
allows	O
accurate	O
control	O
of	O
dimensions	O
and	O
aspect	B-Device
ratios	I-Device
in	O
SiNWs	B-Algorithm
and	O
has	O
been	O
used	O
to	O
obtain	O
high	O
aspect	B-Device
ratio	I-Device
SiNWs	B-Algorithm
with	O
diameters	O
below	O
5nm	O
.	O
</s>
<s>
The	O
self-limiting	O
oxidation	O
of	O
SiNWs	B-Algorithm
is	O
of	O
value	O
towards	O
lithium	B-Language
ion	O
battery	O
materials	O
.	O
</s>
<s>
The	O
orientation	O
of	O
SiNWs	B-Algorithm
has	O
profound	O
influence	O
on	O
the	O
structural	O
and	O
electronic	O
properties	O
of	O
the	O
systems	O
.	O
</s>
<s>
For	O
this	O
reason	O
several	O
procedures	O
have	O
been	O
proposed	O
for	O
the	O
alignment	O
of	O
nanowires	B-Architecture
in	O
chosen	O
orientations	O
.	O
</s>
<s>
There	O
is	O
significant	O
interest	O
in	O
SiNWs	B-Algorithm
for	O
their	O
unique	O
properties	O
and	O
the	O
ability	O
to	O
control	O
size	O
and	O
aspect	B-Device
ratio	I-Device
with	O
great	O
accuracy	O
.	O
</s>
<s>
Combined	O
studies	O
of	O
synthesis	O
methods	O
,	O
oxidation	O
kinetics	O
and	O
properties	O
of	O
SiNW	B-Algorithm
systems	O
aim	O
to	O
overcome	O
the	O
present	O
limitations	O
and	O
facilitate	O
the	O
implementation	O
of	O
SiNW	B-Algorithm
systems	O
,	O
for	O
example	O
,	O
high	O
quality	O
vapor-liquid-solid	O
–	O
grown	O
SiNWs	B-Algorithm
with	O
smooth	O
surfaces	O
can	O
be	O
reversibly	O
stretched	O
with	O
10%	O
or	O
more	O
elastic	O
strain	O
,	O
approaching	O
the	O
theoretical	O
elastic	O
limit	O
of	O
silicon	O
,	O
which	O
could	O
open	O
the	O
doors	O
for	O
the	O
emerging	O
“	O
elastic	O
strain	O
engineering	O
”	O
and	O
flexible	O
bio-/nano	O
-electronics	O
.	O
</s>
