Oxide nanoparticles based electrical and electrochemical devices on paper substrates
L. Pereira, L. Santos, P. Grey, J.T. Carvalho, D. Gaspar, E. Fortunato and R. Martins
CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e
Tecnologia, FCT, Universidade Nova de Lisboa and CEMOP-UNINOVA
Campus da Caparica, 2829-516 Caparica (Portugal)
The growing demand of new and sustainable consumer printed electronics led to the
increased interest in electric and electrochemical devices on paper substrates. Here we
present the wok resulting from recent research concerning the combination of oxide
nanoparticles with cellulosic materials. Four main topics will be addressed: i) enhancement
electrochromic performance
via
metal oxide nanoparticles engineering, (ii) functionalization
of cellulose fibers with oxide nanoparticles (iii) printed and (iv) written semiconductor layers
to be used in transistors and simple circuits on paper substrates.
First topic is related to nanostructured electrochromic printed films with controllable dual
phase (amorphous matrix with embedded nanoparticles,
a
-WO
3
/
ortho
-WO
3
.0.33H
2
O), which
show an optical density 80% higher than amorphous ones, in parallel with improved
coloration efficiency and response time (below 3s). Second topic to be addressed is the
functionalization of cellulose substrates with ZnO nanoparticles obtained via wet chemical
precipitation at room temperature. After being functionalized paper can act as physical
support as well as semiconductor and dielectric in field effect transistors that present on/off
current ratios above 100. Finally, printable inks based on commercial ZnO NPs mixed with a
cellulose derivative were developed to create printed channel layers at temperatures lower
than 150 °C. This allowed the development of fully screen-printed EGTs with mobility above
1 cm
2
V
-1
s
-1
and on/off current ratio close to 10
4
. The same kind of approach was used to
prepare inks that can be written, resulting in dense NPs matrix with sufficient interparticle
connectivity to be used in hybrid handdrawn/printed UV-sensors, transistors and logic gates.
Corresponding author: Luis Pereira,
I 4
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