Paper has emerged as a potential substrate for biodegradable
and
sustainable electronics. In this work, high-performance flexible organic
transistors on a paper substrate were demonstrated using simply an
engineered bilayer gate dielectric consisting of polyvinyl alcohol
(PVA) and polyacrylic acid (PAA), which was previously reported by
us on flexible plastic substrates. The superstrong hydrogen bonding
between PVA and PAA as confirmed through fourier-transform infrared
(FTIR) spectroscopy makes it a promising bilayer for solution-processed
gate dielectrics, yielding highly reliable flexible transistors. For
a −5 V operation, the devices exhibited high performance with
a field-effect mobility up to 0.5 cm2 V–1 s–1, a near-zero threshold voltage, a high Ion/Ioff ∼
104, and high stability as observed through measurements
for repeatability, bias stress, and cyclic stability for 500 cycles.
High electromechanical stability with negligible variation in performance
was achieved upon application of bending in various ways such as concave,
convex, and twist bending. Resistive load inverters with these p-channel
devices showed decent switching, confirming the suitability of these
transistors in circuit applications. Though the performance of the
devices was degraded upon heating above 50 °C, the devices exhibited
very high environmental stability for more than 30 weeks in ambient
conditions. In addition, a high degree of disintegration was observed
in these paper devices due to the capability of biodegradability in
soil with a biofertilizer.