A facile, high-resolution patterning process is introduced for fabrication of electrolyte-gated transistors (EGTs) and circuits using a photo-crosslinkable ion gel and stencil-based screen printing. The photo-crosslinkable gel is based on a triblock copolymer incorporating UV-sensitive terminal azide functionality and a common ionic liquid. Using this material in conjunction with conventional photolithography and stenciling techniques, well-defined 0.5–1 µm thick ion gel films are patterned on semiconductor channels as narrow as 10 µm. The resulting n-type ZnO EGTs display high electron mobility (>2 cm 2 Vs −1 ) and on/off current ratios (>10 5 ). Further, EGT-based inverters exhibit static gains >23 at supply voltages below 3 V, and five-stage EGT ring oscillator circuits display dynamic propagation delays of 50 µs per stage. In general, the screen printing and photo-crosslinking strategy provides a clean room-compatible method to fabricate EGT circuits with improved sensitivity (gain) and computational power (gain × oscillating frequency). Detailed device analysis indicates that significantly shorter delay times, of order 1 µs, can be obtained by improving the ion gel conductance.
- electrolyte-gated transistors
- ion gels
- screen printing
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Reporting period for MRSEC
- Period 6