Solution-Processed ZTO TFTs With Recessed Gate and Low Operating Voltage

IEEE Electron Device Lett.

et al. 2011

Fast and stable zinc-tin-oxide (ZTO) thin-film transistor (TFT) circuits were fabricated by simple and effective solution processing. The solution-processed ZTO TFTs have shown saturation mobility > 2.5 ± 0.29 cm 2 /V · s (W/L = 100/10 μm) and subthreshold slope < 0.4 ± 0.122 V/dec. The ZTO sevenstage ring oscillators have shown an oscillation frequency of ∼800 kHz with a supply voltage V DD = 60 V, corresponding to a propagation delay of < 90 ns per stage. In addition, with appropriate passivation onto the semiconductor channel area, the circuits have shown relatively stable operation even at a gate and source/drain bias voltage of > 50 V for several hours.Index Terms-Ring oscillator, solution process, thin-film transistor (TFT), zinc-tin-oxide (ZTO).

Section: Resultsmentioning

confidence: 99%

Fast and Stable Solution-Processed Transparent Oxide Thin-Film Transistor Circuits

IEEE Electron Device Lett.

et al. 2011

“…A high-j dielectric, ZrO 2 , was deposited from solution by a sol-gel route. 34 Source and drain (S/D) electrodes consisting of a Ti/ Au (3 nm/35 nm) double layer were deposited by thermal evaporation followed by the lift-off process. After the deposition of S/D electrodes, the dielectric surface was treated by UV light in air for 10 min to modify its surface characteristics so as to achieve a spatially uniform network of CNTs upon inkjet printing.…”

mentioning

confidence: 99%

Fluoropolymer coatings for improved carbon nanotube transistor device and circuit performance

Jang

Applied Physics Letters

Geier

et al. 2014

Self Cite

Articles you may be interested inHigh-performance carbon-nanotube-based complementary field-effect-transistors and integrated circuits with yttrium oxide Appl. Phys. Lett. 105, 063101 (2014); 10.1063/1.4892918High performance transistors via aligned polyfluorene-sorted carbon nanotubes Appl. Phys. Lett.We report on the marked improvements in key device characteristics of single walled carbon nanotube (SWCNT) field-effect transistors (FETs) by coating the active semiconductor with a fluoropolymer layer such as poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE). The observed improvements include: (i) A reduction in off-current by about an order of magnitude, (ii) a significant reduction in the variation of threshold voltage, and (iii) a reduction in bias stress-related instability and hysteresis present in device characteristics. These favorable changes in device characteristics also enhance circuit performance and the oscillation amplitude, oscillation frequency, and increase the yield of printed complementary 5-stage ring oscillators. The origins of these improvements are explored by exposing SWCNT FETs to a number of vapor phase polar molecules which produce similar effects on the FET characteristics as the PVDF-TrFE. Coating of the active SWCNT semiconductor layer with a fluoropolymer will be advantageous for the adoption of SWCNT FETs in a variety of printed electronics applications. V C 2014 AIP Publishing LLC.

“…Two layers of high-j ZrO 2 dielectric (thickness 90-100 nm) were deposited on a heavily doped Si wafer (which was employed as the gate) using a sol-gel route. 29 The dielectric surface was exposed to UV light in air for 10 min, causing the surface to become more hydrophilic, facilitating the deposition of the ZTO layer. The thickness of the ZTO layer (30-40 nm), the inkjet printing of the ZTO solution was repeated 4 times.…”

Section: Inkjet Printed Ambipolar Transistors and Inverters Based On mentioning

confidence: 99%

“…The substrate temperature during printing was maintained at 60 C. 30 Following inkjet printing, the substrate was annealed on a hotplate at 500 C for an hour in air to facilitate the conversion of the ZTO precursor film to amorphous ZTO, as described previously. 28,29 After annealing, the source and drain electrodes consisting of a bilayer of Ti (3 nm) and Au (50 nm) were patterned by photolithography and lift-off. Next, the surface of ZTO film was exposed to UV light in air for 10 min to promote the wetting of the SWCNT ink.…”

Section: Inkjet Printed Ambipolar Transistors and Inverters Based On mentioning

confidence: 99%

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Inkjet printed ambipolar transistors and inverters based on carbon nanotube/zinc tin oxide heterostructures

Applied Physics Letters

Jang

Geier

et al. 2014

Self Cite

We report ambipolar field-effect transistors (FETs) consisting of inkjet printed semiconductor bilayer heterostructures utilizing semiconducting single-walled carbon nanotubes (SWCNTs) and amorphous zinc tin oxide (ZTO). The bilayer structure allows for electron transport to occur principally in the amorphous oxide layer and hole transport to occur exclusively in the SWCNT layer. This results in balanced electron and hole mobilities exceeding 2 cm2 V−1 s−1 at low operating voltages (<5 V) in air. We further show that the SWCNT-ZTO hybrid ambipolar FETs can be integrated into functional inverter circuits that display high peak gain (>10). This work provides a pathway for realizing solution processable, inkjet printable, large area electronic devices, and systems based on SWCNT-amorphous oxide heterostructures.