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there was little discussion regarding optical properties of the particles.
18
Likewise, the reaction of metal alkyls with silylated phosphines produced
adduct compounds that were used as precursor to metal phosphides,
although some metal impurities were also observed.
19
The group of Wells
explored new routes to GaAs using precursors using precursors such as
AsCl
3
Ga
2
, prepared by reacting GaCl
3
with As(SiMe
3
)
3
, which was then
washed in hot hydrocarbons followed by heating up to 410
C under an
inert atmosphere.
20
Similarly, the single-source precursor [X
2
GaP(SiMe
3
)
2
]
2
(X
d
n
1
y
4
n
g
|
3
Cl, Br, I) was prepared by the reaction of GaCl
3
with P(SiMe
3
)
3
, which
could then be thermolysed to give bulk GaP.
21,22
The same reactions using
indium halides with either As(SiMe
3
)
3
or P(SiMe
3
)
3
gave similar precursors to
those described above, which could all be used to prepare bulk III
¼
-
V
compounds by thermolysis.
23
The
V QDs using the dehalosilylation reaction
was reported by Olshavsky
et al.
,
24
who carried out the reaction between
GaCl
3
and As(SiMe
3
)
3
in quinoline at 240
C for 3 days, followed by
rst solution route to III
-
ame-
annealing the product under vacuum, which improved the crystallinity but
reduced the solubility of the material presumably by removing the surface
species. The particles,
ca.
4.5
3.5 nm in size, were zinc blende in structure
with an excitonic peak in the absorption spectra at
ca.
500 nm, shi
ing from
the bulk band edge of
ca.
850 nm. This report is notable as the
rst to explore
the e
ects of quantum con
nement using the theoretical
framework
provided by Brus, exploring the e
nement of the
optical properties. Interestingly, the presence of molecular species in solu-
tion and on the particle surface was reported to interfere with the optics,
25
which is signi
ects of quantum con
.
cant as this was highlighted again in later years as a problem
with III
rming the solvent molecules coordi-
nated to the particle surface. Another report
26
-
V QD synthesis, while con
on the same reaction
described the use of di
ering solvents, such as trioctylamine (TOA) and
hexadecane which provided higher synthesis temperatures. A similar reac-
tion using In(OH)
3
and As(SiMe
3
)
3
in triglyme gave 4 nm InAs particles with
a band edge of approximately 500 nm, and broad emission at approximately
550 nm.
27
2.2 Group III
Phosphides
-
Micic
et al.
were the
rst to report the incorporation of the dehalosilylation
reaction with the high-temperature,
28
inert-atmosphere reaction using TOPO
as a surfactant, inspired by the work of Murray
et al.
described earlier. In this
case, chloroindium oxalate and P(SiMe
3
)
3
of varying molar ratios were mixed
at room temperature to form an unidenti
ed precursor, which was then
heated to 270
C with either TOPO or a mix of TOPO and trioctylphosphine
(TOP) for several days, giving slightly phosphorus-rich InP QDs of approxi-
mately 2.5 nm diameter with a narrow size distribution, passivated with the
surfactant(s) in at least two bonding con
gurations.
29
The particles are
notable for being reportedly the
rst examples of InP to exhibit an excitonic
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