Environmental Engineering Reference
In-Depth Information
to-roll mass basis similar to a modern printing press. The next
gure shows one
possible step-by-step prescription for CuIn
1
x
Ga
x
Se
2
CIGS cell manufacture that
does not require vacuum equipment. (Many variations are possible, including those
that avoid CdS and also those in which the substrate is simply aluminum foil.)
Figure 6.11, top to bottom, shows steps in one version of an ink-printing approach
to CIGS solar cell formation. Substrates are either glass coated with Mo or a Mo foil,
which can be thin and
exible. The CIGS absorber layer is formed in steps 2
-
5. The
absorber is chemically CuIn
1
x
Ga
x
Se
2
. The Cu, In, and Ga metal components are
printed onto the cell in the form of oxide nanoparticles suspended in liquid, that is, a
water-based ink. This is inherently ef
cient with regard to the use of the expensive
elements, and the formulation of the ink allows close control of the composition. The
layer is reduced (the oxygen is removed) by heating in a reducing atmosphere of
Figure 6.11
Ink-printed nonvacuumapproach [75] to fabricate CuIn
1x
Ga
x
Se
2
solar cells on flexible
substrates.
