Chemistry Letters Vol.34, No.11 (2005)
1527
used to control the size of nanocrystals formed in the solution
phase, resulting in two discrete narrower size distributions than
previously published procedures.11,12,16 Future work will opti-
mize these conditions, to further control the size distribution
of germanium nanocrystals.
A
We thank the imaging center assistance with the TEM.
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Figure 3. a) Size selective photoluminescence spectra 2–4 nm
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ꢀ
fringe spacing of 3.27 A is consistent with h111i plane of germa-
nium. This distribution is much narrower than those previously
achieved using inverse micelle (1–10 nm) or metathesis reac-
tions (1–10 nm).11,12,16
Figure 3a, shows the photoluminescence (PL) spectra for the
2–4 nm germanium nanocrystals which exhibit photolumines-
cence in a relatively narrow region of 420–430 nm with an exci-
tation from 310–340 nm. A less intense region is resolved to
480 nm with excitation wavelengths of 350–380 nm. Figure 3b,
shows the PL spectra for the 5–9 nm germanium nanocrystals
which exhibit photoluminescence in a relatively narrow region
of 450–470 nm with an excitation of 330–360 nm. A less intense
region is resolved to 500 nm with excitation wavelengths
from 370–410 nm, which is consistent with previously reported
studies and with the quantum confinement model.11,12,16
In conclusion, the initial concentration of germanium can be
Published on the web (Advance View) October 15, 2005; DOI 10.1246/cl.2005.1526