Environmental Engineering Reference
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Fig. 27 Schematic diagram of the ideal lamination process and embedded images of the
patterned Silver layer (left) and Laminated device (right)
spin-coated on the ITO-PET or ITO-glass. The P3HT:PC 61 BM was spin-coated on
the ZnO nanoparticle layer. On a separate PET substrate, the Ag nanoparticle ink
was spin-coated, and then the PEDOT:PSS was spin-coated over the silver film.
Finally, the two parts were laminated together on the hot plate at 130 C for 5 min.
The Ag electrode was patterned previously to have a role of the anode. Figure 35
shows the proposed continuous process to produce large area OPVs by using
lamination technique. Because the metal film could not infiltrate through the voids
or defects in the active layer, the lamination process is helpful to maintain the high
shunt resistance in the large-scale devices. Moreover, the PET substrate acts as a
barrier film preventing the oxygen and moisture from diffusing into the Ag layer
and the active polymer layer.
The power conversion efficiency of the laminated device is 2.76 % using the
ITO glass in the small area device (1 mm diameter, Fig. 28 ) as summarized in
Table 11 . The device performance of the ITO-glass is better than the ITO-PET,
because the sheet resistance of the ITO-glass was 10 X/sq and the ITO-PET was
20 X/sq.
For larger device low-band gap polymer (iI-T3) was used. The ZnO nanopar-
ticle layer and polymer active layer was blade-coated to 30 and 100 nm thickness
respectively. The device performance is promising for the large area devices
(2 and 3 cm 2 ). Generally, when the device size is increased, shunt resistance is
decreased. The shunt resistance of the lamination processed device is higher than
that of the evaporated device. In the large-size device, the efficiency of the opti-
mized device was 2.27 % for 3 cm 2 devices as shown in Table 12 . The series
resistance was reduced after the thermal annealing (Table 14 ), due to improved
contact at the laminated interface.
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