Study of Surface-Modified PVP Gate Dielectric in Organic Thin Film Transistors with the Nano-Particle Silver Ink Source/Drain Electrode

Abstract

We have fabricated the flexible pentacene based organic thin film transistors (OTFTs) with formulated poly[4-vinylphenol] (PVP) gate dielectrics treated by CF4/O2 plasma on poly[ethersulfones] (PES) substrate. The solution of gate dielectrics is made by adding methylated poly[melamine-co-formaldehyde] (MMF) to PVP. The PVP gate dielectric layer was cross linked at 90 degrees under UV ozone exposure. Source/drain electrodes are formed by micro contact printing (MCP) method using nano particle silver ink for the purposes of low cost and high throughput. The optimized OTFT shows the device performance with field effect mobility of the 0.88 cm2/V s, subthreshold slope of 2.2 V/decade, and on/off current ratios of 1.8 x 10(-6) at -40 V gate bias. We found that hydrophobic PVP gate dielectric surface can influence on the initial film morphologies of pentacene making dense, which is more important for high performance OTFTs than large grain size. Moreover, hydrophobic gate dielelctric surface reduces voids and -OH groups that interrupt the carrier transport in OTFTs.

Agarose‐Assisted Micro‐Contact Printing for High‐Quality Biomolecular Micro‐Patterns

“…As this method could selectively print organic self‐assembled monolayers, polymers, or nanomaterials, spatial control of surface characteristics, such as wettability, has been available . In addition, facile fabrication of functional substrates such as plasmonic sensors or electronics with conductive materials have been also recently reported using μCP. But most of all, this micropatterning technique has been highlighted because of its ability to pattern biomolecules, thus enabling the design of cellular microenvironments in biological experiments and tissue engineering applications.…”