1. Low-voltage organic thin-film transistors with π-σ-phosphonic acid molecular dielectric monolayers
- Author
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Guy Ting, Jae-Won Ka, Hin-Lap Yip, Orb Acton, Richard Schofield, Alex K.-Y. Jen, Hong Ma, and Neil M. Tucker
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Transistor ,Dielectric ,Subthreshold slope ,law.invention ,Pentacene ,Organic semiconductor ,chemistry.chemical_compound ,chemistry ,Thin-film transistor ,law ,Monolayer ,Optoelectronics ,business ,Low voltage - Abstract
Pentacene-based organic thin-film transistors (OTFTs) have been fabricated using π-σ-phosphonic acid self-assembled monolayers (SAMs) on top of aluminum oxide as the gate dielectrics. With ultrathin dielectrics, high capacitances up to 760nF∕cm2 and low leakage current densities of 10−8A∕cm2 at 2V could be obtained, allowing operation of OTFTs within −3V. Vast improvements in the gate leakage current (∼2 orders), on/off current ratio (1 order), and subthreshold slope down to 85mV∕decade are achieved compared to control devices without SAMs. The OTFTs with pentacene vapor deposited at room temperature on SAM dielectrics-modified substrates exhibit mobilities of 0.14–0.30cm2∕Vs, on/off current ratios of 105, and threshold voltages of −(1.3–1.5)V.
- Published
- 2008
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