Films minces à base de Si nanostructuré pour des cellules ...

CA sample is estimated as 4nm.
4.5.6 High Resolution-Transmission Electron Microscopy
In order to determine the location of nanocrystals, HR-TEM investigations were
carried out on CA 100(3.5/5) ML. The microstructure displayed in gure 4.23a
shows 100 patterns of perfectly alternated SRSO and SRSN sublayers deposited on
a Si substrate (dark part on the bottom). The bright and dark contrasts observed
in the lm correspond to the SRSO and SRSN sublayers respectively. At this scale,
it is not possible to correlate these observations to the ones performed above, on the
surface of the lm (ref. Fig. 4.21).
tel-00916300, version 1 - 10 Dec 2013
(a) General microstructure and electron diraction pattern.
(b) Dark eld image with Si(111) re-
ection. The Si-np are highlighted
with a circle around them.
Figure 4.23: TEM images of CA 100(3.5/5) ML.
The inset of gure 4.23a corresponds to the electron diraction pattern of the
lm. It reveals the presence of (111), (220) and (311) rings that are the signatures
of Si nanocrystal formation in the ML. The corresponding (111) dark eld image
reveals that the Si nanocrystals are conned in the SRSO sublayers and the brighter
SRSN sublayers are devoid of nanocrystals (Fig. 4.23b). A HR-TEM image of this
ML (Fig. 4.24) shows the detailed microstructure of the lm at the nanometer scale.
112