9 Si Nanopowder for Photoluminescence and Hydrogen Generation Materials
355
9.1.2 Experiments
Si swarf generated during slicing of Si ingots by use of the fixed-abrasive wire
saw method was used as a starting material. After cleaning with organic solvent
to remove coolant and other organic species, Si swarf was milled with a ball mill
apparatus followed by beads milling with zirconia beads [16–19]. For one-step
beads milling, 0.5 μm diameter beads were used, while for two-step beads milling,
subsequent milling was performed with 0.3 μm beads. The following two different
methods were employed for production of green-PL and blue-PL Si nanopowder:
To obtain green-PL Si nanopowder, fabricated nanopowder was etched with an HF
solution, followed by centrifugation and filtration, and then, it was immersed in
ethanol. For fabrication of blue-PL Si nanopowder, milled swarf was filtered using
a Teflon membrane filter, followed by immersion in hexane solvent.
Transmission electron micrography (TEM) measurements were performed using
an EM-3000F (JEOL) microscope with 300 keV incident electrons. X-ray diffraction (XRD) measurements were carried out by use of a Rigaku SmartLab diffractometer. Photoluminescence (PL) spectra were recorded using a Hitachi HighTechnologies Corporation F-7000 spectrometer. Ultraviolet and visible light (UVVis) absorption spectra were measured by use of a JASCO V-570 spectrometer.
Time-dissolved PL measurements were carried out using a HORIBA DeltaFlex
photometer.
9.1.3 Results and Discussion
9.1.3.1 Structure of Si Nanopowder
Figure 9.1a shows the TEM micrograph of Si nanopowder fabricated by the onestep beads milling method from Si swarf. The TEM observation was performed
after etching with an HF solution to remove amorphous SiO 2 . Many crystallites
with polygonal shapes and sizes less than 10 nm are clearly observed.
Fig. 9.1 TEM micrographs
of Si nanopowder fabricated
from Si swarf using the
following beads milling
methods: (a) one-step
milling, (b) two-step milling
(a)
10 nm
(b)
10 nm
355
9.1.2 Experiments
Si swarf generated during slicing of Si ingots by use of the fixed-abrasive wire
saw method was used as a starting material. After cleaning with organic solvent
to remove coolant and other organic species, Si swarf was milled with a ball mill
apparatus followed by beads milling with zirconia beads [16–19]. For one-step
beads milling, 0.5 μm diameter beads were used, while for two-step beads milling,
subsequent milling was performed with 0.3 μm beads. The following two different
methods were employed for production of green-PL and blue-PL Si nanopowder:
To obtain green-PL Si nanopowder, fabricated nanopowder was etched with an HF
solution, followed by centrifugation and filtration, and then, it was immersed in
ethanol. For fabrication of blue-PL Si nanopowder, milled swarf was filtered using
a Teflon membrane filter, followed by immersion in hexane solvent.
Transmission electron micrography (TEM) measurements were performed using
an EM-3000F (JEOL) microscope with 300 keV incident electrons. X-ray diffraction (XRD) measurements were carried out by use of a Rigaku SmartLab diffractometer. Photoluminescence (PL) spectra were recorded using a Hitachi HighTechnologies Corporation F-7000 spectrometer. Ultraviolet and visible light (UVVis) absorption spectra were measured by use of a JASCO V-570 spectrometer.
Time-dissolved PL measurements were carried out using a HORIBA DeltaFlex
photometer.
9.1.3 Results and Discussion
9.1.3.1 Structure of Si Nanopowder
Figure 9.1a shows the TEM micrograph of Si nanopowder fabricated by the onestep beads milling method from Si swarf. The TEM observation was performed
after etching with an HF solution to remove amorphous SiO 2 . Many crystallites
with polygonal shapes and sizes less than 10 nm are clearly observed.
Fig. 9.1 TEM micrographs
of Si nanopowder fabricated
from Si swarf using the
following beads milling
methods: (a) one-step
milling, (b) two-step milling
(a)
10 nm
(b)
10 nm