We developed a rapid APPJ sintering process for nanoporous
SnO2 materials. An APPJ-sintered (for 30 s) nanoporous SnO2
revealed properties comparable to those of furnace-sintered (for
1h) SnO2. With the increase in APPJ-sintering time, the electrical
conductivity increases and then decreases, activation energy of
electrical conductivity decreases and then increases, the slope of the
optical absorption edge decreases and then increases, and the
bandgap decreases and then increases. All of thesefindings imply a
modulation of bandtail and defectstates in the materials. It is
therefore suggested that the prolonged APPJ-sintering process
should be practically avoided. This sequential screen-printing and
APPJ-sintering process can be further developed into a roll-to-roll
process, which can lower the cost and increase the fabrication
throughput. The sintered highly nanoporous oxides have high
surface-to-volume ratios, and therefore, they can potentially be
used for gas sensors or catalysts in which large reactive surfaces are
demanded.