Chemistry Reference
In-Depth Information
d
n
1
y
4
n
g
|
2
Figure 4.2
Surface plasmon resonance (SPR) in the absorption spectrum of 6 nm
diameter Cu
2
x
S QDs in three dierent solvents (CCl
4
,
tetrachlorethylene (TCE), CS
2
). Inset shows the shi
in SPR with
refractive index. Reprinted by permission from Macmillan Publishers
Ltd:
Nat. Mater.
, J. M. Luther, P. K. Jain, T. Ewers and A. P. Alivisatos,
Nat. Mater.
, 2011, 10, 361. Copyright 2011.
.
route yielded di
erent polymorphs which maintained the disc shape,
yielding either CuS or Cu
1.8
S particles depending on precursor concentra-
tion.
28
The use of a thiol to form an
in situ
copper thiolate which was then
thermolysed in the presence of TOPO has also been reported, giving mono-
dispersed particles which easily self-assembled on a substrate.
29
The selenides can also be prepared by similar methods, using hexadecyl-
amine (HDA), TOPSe and Cu(CH
3
C(O)CH
2
C(O)CH
3
)
2
at 150
C for 2 hours,
giving Cu
2
x
Se particles with a cubic crystalline core.
30
The particle size could
be tuned between
ca.
5 and 8 nm by increasing the amount of precursor.
Single-crystal nanoplates or nanosheets (depending on precursor ratio) of
Cu
2
x
Se have also been grown using CuCl, 2-ethylhexanoic acid and OAm at
80
C, which was injected into a para
n/selenium solution at 250
C.
31
The
resulting 2D materials had absorption spectra in the near infrared region of
the spectra.
Interestingly, other selenium sources have been explored, notably the air-
stable compound 1,3-dimethylimidazoline-2-selenone, a simply prepared
precursor which was dissolved in CH
2
Cl
2
and OAm, and injected into CuCl
2
Search WWH ::
Custom Search