1. Pentacene-Based Low-Voltage Strain Sensors With PVP/$ \hbox{Ta}_{2}\hbox{O}_{5}$ Hybrid Gate Dielectrics
- Author
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Soyoun Jung, Vijay K. Varadan, and Taeksoo Ji
- Subjects
Materials science ,Wheatstone bridge ,business.industry ,Electrical engineering ,Electronic, Optical and Magnetic Materials ,law.invention ,Threshold voltage ,Pentacene ,chemistry.chemical_compound ,chemistry ,Thin-film transistor ,law ,Tantalum pentoxide ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Polyethylene naphthalate ,Low voltage ,High-κ dielectric - Abstract
Field-controllable pentacene-semiconductor-based strain sensors were fabricated with hybrid gate dielectrics using polyvinyl phenol (PVP) and high-k inorganic tantalum pentoxide (Ta2O5) onto polyethylene naphthalate films. The Ta2O5 gate-dielectric layer combined with a thin PVP layer to form very smooth and hydrophobic surfaces turns out to improve the molecular structures of pentacene films significantly. The PVP-Ta2O5 hybrid-gate-dielectric films exhibit a high dielectric constant of 19.27 and a leakage-current density of as low as 100 nA/cm2 . The sensors employing a thin-film-transistor-like Wheatstone bridge configuration able to operate at reduced voltage (~ 4 V) show good device characteristics with a field-effect mobility of 1.89 cm2/V · s and a threshold voltage of -0.5 V. The strain sensor characterized with bending at 45° with respect to the bridge bias direction with different bending radii of 50-, 40-, 30-, 20-, and 8-mm displays output signals improved in linearity in a low range of operating voltages.
- Published
- 2010
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