Thin films and nanostructured coatings for eco-efficient buildings - Nanotechnology in Eco-efficient Construction - page 176

Sputter deposition

Sputter cathode
Vacuum chamber

Unheated glass
Sputter plasma (a)

Spray pyrolysis

Spray nozzle
Aerosol

(b)

Heated glass

8.15 Principles for sputter deposition (a) and for spray pyrolysis
(b) to coat surfaces of glass transported as indicated by the horizontal
arrows. From Granqvist (1991).

of sheet glass in order to make thin fi lms that can give low thermal emission
and thereby good thermal insulation in a double-glazed window, or thin
fi lms that control the throughput of solar energy so that the need for air
conditioning is diminished. Figure 8.15 shows two principles of how this is
done (Granqvist, 1991): panel (a) illustrates sputtering onto moving sheet
glass in a continuous process wherein panes are entering though a load lock
at one end of a deposition unit and exiting at the other end, and panel (b)
demonstrates another technique based on spray deposition of a metal-
containing solution onto hot glass, most conveniently as the sheet glass
emerges from the leer during fl oat glass production. More detailed discus-
sions of glass coating are given elsewhere, in particular in topics and papers
by Gläser (2000, 2008) and by Bach and Krause (2003). The practical depo-
sition systems - particularly for sputter deposition - can be very large and
involve a multitude of sputter targets mounted along a production line that
is more than 100 m in length; Fig. 8.16 is a photograph of a system of this
kind.
'Web coating' of fl exible substrates (Schiller et al. , 2000; Fahlteich et al. ,
2012) is a well-developed technology with possibilities for excellent process
control. It can be used to make thin fi lms cost-effectively on very large

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