High Electron Mobility in Vacuum and Ambient for PDIF-CN2 Single-Crystal Transistors

TL;DR

This study demonstrates high electron mobility in PDIF-CN2 single-crystal transistors operating in vacuum and ambient conditions, showing potential for high-performance n-type organic field-effect transistors.

Contribution

It reports the first observation of high electron mobility in PDIF-CN2 single-crystal transistors under ambient conditions, using a PMMA gate dielectric to reduce surface trapping.

Findings

Electron mobility of 6 cm²/Vs in vacuum

Electron mobility of 3 cm²/Vs in air

Potential for high-performance n-type OFETs

Abstract

We have investigated the electron mobility on field-effect transistors based on PDIF-CN$_{2}$ single crystals. The family of the small molecules PDI8-CN$_{2}$ has been chosen for the promising results obtained for vapour-deposited thin film FETs. We used as gate dielectric a layer of PMMA (spinned on top of the SiO$_{2}$), to reduce the possibility of electron trapping by hydroxyl groups present at surface of the oxide. For these devices we obtained a room temperature mobility of 6 cm$^{2}$/Vs in vacuum and 3 cm$^{2}$/Vs in air. Our measurements demonstrate the possibility to obtain n-type OFETs with performances comparable to those of p-type devices.