1 research outputs found
High-Performance Sub-Micrometer Channel WSe<sub>2</sub> Field-Effect Transistors Prepared Using a FloodāDike Printing Method
Printing technology has potential
to offer a cost-effective and
scalable way to fabricate electronic devices based on two-dimensional
(2D) transition metal dichalcogenides (TMDCs). However, limited by
the registration accuracy and resolution of printing, the previously
reported printed TMDC field-effect transistors (FETs) have relatively
long channel lengths (13ā200 Ī¼m), thus suffering low
current-driving capabilities (ā¤0.02 Ī¼A/Ī¼m). Here,
we report a āfloodādikeā self-aligned printing
technique that allows the formation of source/drain metal contacts
on TMDC materials with sub-micrometer channel lengths in a reliable
way. This self-aligned printing technique involves three steps: (i)
printing of gold ink on a WSe<sub>2</sub> flake to form the first
gold electrode, (ii) modifying the surface of the first gold electrode
with a self-assembled monolayer (SAM) to lower the surface tension
and render the surface hydrophobic, and (iii) printing of gold ink
close to the SAM-treated first electrode at a certain distance. During
the third step, the gold ink would first spread toward the edge of
the first electrode and then get stopped by the hydrophobic SAM coating,
ending up forming a sub-micrometer channel. With this printing technique,
we have successfully downscaled the channel length to ā¼750
nm and achieved enhanced on-state current densities of ā¼0.64
Ī¼A/Ī¼m (average) and high on/off current ratios of ā¼3
Ć 10<sup>5</sup> (average). Furthermore, with our high-performance
printed WSe<sub>2</sub> FETs, driving capabilities for quantum-dot
light-emitting diodes (LEDs), inorganic LEDs, and organic LEDs have
been demonstrated, which reveals the potential of using printed TMDC
electronics for display backplane applications