Effects of polarized organosilane self-assembled monolayers on organic single-crystal field-effect transistors

TL;DR

This study investigates how polarized organosilane self-assembled monolayers influence the electrical properties of organic single-crystal transistors, revealing charge injection effects and threshold voltage shifts.

Contribution

It demonstrates that polarized SAMs can induce nanoscale charge injection and shift threshold voltages without increasing subthreshold swing in organic transistors.

Findings

SAM polarization shifts threshold voltage

Charge injection up to ~10^12 cm^-2 observed

Subthreshold swing remains very low at 0.11 V/decade

Abstract

The surface conductivity is measured by a four-probe technique for pentacene and rubrene single-crystals laminated on polarized and nearly unpolarized molecular monolayers with application of perpendicular electric fields. The polarization of the self-assembled monolayers (SAMs) shifts the threshold gate voltage, while maintaining a very low subthreshold swing of the single-crystal devices (0.11 V/decade). The results, excluding influences of parasitic contacts and grain boundaries, demonstrate SAM-induced nanoscale charge injection up to ~10^12 cm^-2 at the surface of the organic single crystals.