Realization of Ohmic-contact and velocity saturation in organic field-effect transistors by crystallized monolayer

TL;DR

This paper demonstrates that using crystallized monolayer organic crystals in OFETs achieves Ohmic contacts and velocity saturation, enabling high current density and improved device performance, with implications for flexible electronics.

Contribution

It introduces a novel approach with monolayer organic crystals to realize Ohmic contacts and observe velocity saturation in OFETs, advancing high-performance flexible electronics.

Findings

Intrinsic mobility of 12.5 cm2V-1s-1 achieved

Ohmic contact resistance of 40 ohm-cm demonstrated

High current density of 4.2 μA/μm observed

Abstract

The contact resistance limits the down-scaling and operating range of OFETs. With the monolayer (1L) organic crystals and non-destructive metal/semiconductor interfaces, intrinsic mobility of 12.5 cm2V-1s-1 and Ohmic contact resistance of 40 ohm-cm were achieved. The on/off ratio maintained at 10^3 even at a small VDS of -0.1 mV. High current density of 4.2 uA/um was achieved with the 1L-crystal as the active layer. At such high current density, the velocity saturation and channel self-heating effects are observed in OFETs for the first time. In addition to the low contact resistance and high-resolution lithography, we suggest the thermal management of the high mobility OFETs will be the next major challenge to achieve high-speed densely integrated flexible electronics.