Indium Tin Oxide-Free Polymer Solar Cells: Toward Commercial Reality - Low-cost Nanomaterials: Toward Greener and More Efficient Energy Applications - page 201

Fig. 13 High intensity pulse
laser sintering of as-deposited
AgNW films. Cross-sectional
SEM images of AgNW films
on PET substrates a before
and b and c after HIPL
sintering with light intensities
of 1.14 and 2.33 J cm -2 ,
respectively. 2013 RSC
Publishing.Reprinted, with
permission from Ref. [ 41 ]
Other methods include Meyer rod coating in which a metal nanowire suspension is
placed on the substrate and a Meyer rod is pulled over it. Using this method, an
8 9 8 inch substrate has been prepared [ 38 ].
Although the solution-based nature of nanowire inks opens wide opportunities
in low-cost processing on large scales using various printing and coating tech-
niques as described in Ref. [ 39 ]; however, the early reports have identified some
challenges that ought to be solved before large-scale processing could be carried
out. For example, the poor adhesion AgNW on substrates, the large junction
resistance, the removal of surfactants present in the ink at temperatures that
flexible substrates such as PET can withstand (\140 C) and the rough topology of
the resulting film. Very recently, the use of photonic sintering methods such as
Direct-Write Pulse Laser Sintering [ 40 ] and High Intensity Pulse Light Sintering
(HIPS) [ 41 ] has achieved successful results at simultaneously eliminating most
challenges associated with AgNW films without sacrificing the properties of the
films (Fig. 13 ).