epdf.pub_nanotechnology-and-nanoelectronics-materials-devic

3.4 Nuclear Track Nanodefects 35
Fig. 3.24 EL from a nanocluster based optoelectronic coupler [35]. 1: LED, 2: detector, 3
and 10: metallic contacts, 7: optical transparent galvanic isolation layer, 4: Si wafer, 5: SiO 2
layer with implanted nanoclusters, 6: optical transparent conductive layer, wafer back contact,
8: optical transparent conductive layer, 9: pin a-Si photodiode
Fig. 3.25 Electroluminescence from porous silicon [38]
The technology of porous silicon has always been connected with the hope of
combining PL with standard silicon technology. These hopes were soon subdued
by the low conversion coefficients, some of which are in the 10 5 range. However,
the full limits of the applicability of po-Si are not yet known.
(iii) It is well-known that the interaction of silicon, oxygen, and hydrogen leads
to EL and PL within the optical range. Section 3.2 shows a CZ wafer that is exposed
to a 13.56 MHz hydrogen plasma at 250 °C for 2 h, followed by a 10 min
oxidation at 600 °C (i.e., exposure to air). Thereafter the wafer shows a strong EL
in addition to the already available PL shown in Fig. 3.6.
3.4 Nuclear Track Nanodefects
3.4.1 Production of Nanodefects with Nuclear Tracks
In the process of irradiating insulators with high-energy ions (typical energies of
100 MeV to 1 GeV) a change of the material in the path area was observed. The