Organic field-effect transistors with low-temperature curable high-k hybrid gate dielectrics

Abstract

We report a low-voltage-operated organic field-effect transistor that uses a hybrid gate insulator that has a high dielectric constant k. The gate insulator consists of a high-k polymer cyanoetylated pullulan (CEP) that can be efficiently cross-linked by glycidoxypropyltrimethoxysilane (GOPTMS) at low temperature (~110°C). The very low curing temperature is below the glass transition temperature Tg of conventional plastic substrates for plastic electronics, and is therefore compatible with many plastic substrates for plastic electronics. The cross-linking is very efficient in that only 1/10 (w:w) GOPTMS: CEP produced densely cross-linked thin films with a smooth surface, good insulating property, high capacitance density and high k. The devices functioned at low voltage, and exhibited charge carrier mobility ~ 1.83 cm2 V-1 s-1, and steep substheshold swing ~88 mV dec-1. These results imply that high quality polymer gate insulators are achievable at low temperature with a very small fraction of blended crosslinking agents; this characteristic offers a method to achieve portable all-plastic flexible electronics that function at low voltage.

Effect of Organic / Inorganic Gate Materials on the Organic Field-Effect Transistors Performance

“…In this region, the drain current becomes independent of the drain voltage; large negative drain voltages are required to achieve saturation. Such behavior indicates that pentacene-based OFETs typically operate in the accumulation mode, which means that holes are the majority carriers and are accumulated in the conductive channel [18,19].…”

“…The linear and saturation regions of transconductance curve of the OFET are described according to the given equations [18]:…”

Pullulan-1-Ethyl-3-Methylimidazolium Tetrafluoroborate Composite as a Water-Soluble Active Component of a Vibration Sensor

“…In another application, PUL has been instrumental in creating high-k polymer cyanoethylated PUL (CEP) thin films for use in organic field-effect transistors. These films exhibit advantages such as low-voltage operation and a high dielectric constant [ 22 ]. Additionally, PUL plays a role in transparent circuit boards and foldable conductive nanopaper for LED lighting, underscoring its potential in electronic circuits and devices [ 23 ].…”