Civil Engineering Reference
In-Depth Information
The market suggests that there is still some time to wait before this tech-
nology will be commercially viable, and it is likely it will be towards the end
of the fi rst quarter of the twenty-fi rst century before it is achieved. It is
anticipated that the third generation will shatter the current price of $1/W
to around $0.20/W (Green, 2003).
12.5
The use of nanotechnology in photovoltaic
(PV) technology
Nanotechnology is related to the direct control of matter on the atomic
scale and it can also be used to describe material, devices or structures with
one of their dimensions being between 1 and 100 nanometres. An atom is
considered the basic building block and has a diameter of 0.1 nm with its
nucleus being smaller at 0.00001 nm. It is diffi cult to actually picture this
size - one nanometre (nm) is equal to one billionth or 10
−9
of a metre. The
size of atoms are not the only factor to consider - as with every industry, it
has its own specifi c assembly methods and in nanotechnology it is split into
two main areas, the bottom-up and top-down approaches, which are sum-
marized in Table 12.8 (Rodger, 2006).
Currently, nanotechnology has been accepted for use in applications
related to surface science, organic chemistry, semiconductor physics, modular
biology and micro-fabrication, but in the future it is expected that this will
expand to include electronics, medicine, biomaterials and energy
production.
If PV technology is to become a good competitor to fossil fuels, it must
be cost competitive. Currently, silicon-based PVs are actually more expen-
sive per kilowatt hour, hence the search for another solution. The nanostruc-
ture confi guration is known to enable control of the electronics, structural
and optical factors, therefore providing it as a possible solution for PVs.
With this under consideration, development of nanotechnology PVs (Anon.,
2010) is expected to increase in the coming years and ameliorate the pro-
blems seen in the fi rst and second generation aiming at lower cost (Anai
et al.
, 2010) by not only reducing material but also ensuring that the manuf-
acturing process is effi cient. Most importantly, the PV industry considers
Table 12.8
Approaches in nanotechnology
Approaches
Description
Bottom-up
Self-assembly by chemical principles of molecular
components using the principle of molecular recognition
Top-down
No atomic-level control as objects are built from larger parts
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