Vertical, electrolyte-gated organic transistors: continuous operation in the MA/cm$^2$ regime and use as low-power artificial synapses

TL;DR

This paper demonstrates a novel vertical electrolyte-gated organic transistor with 40 nm channel length, achieving high current densities and modulation ratios, suitable for low-power artificial synapses and neural network applications.

Contribution

Introduction of a new vertical transistor design with electrolyte gating that achieves high performance in organic polymers at nanoscopic scales.

Findings

High on-state current densities above 3 MA/cm²

On/off current modulation ratios up to 10^8

Large transconductance of up to 5000 S/m

Abstract

Organic semiconductors are usually not thought to show outstanding performance in highly-integrated, sub 100 nm transistors. Consequently, single-crystalline materials such as SWCNTs, MoS2 or inorganic semiconductors are the material of choice at these nanoscopic dimensions. Here, we show that using a novel vertical field-effect transistor design with a channel length of only 40 nm and a footprint of 2 x 80 x 80 nm$^2$, high electrical performance with organic polymers can be realized when using electrolyte gating. Our organic transistors combine high on-state current densities of above 3 MA/cm$^2$, on/off current modulation ratios of up to 108 and large transconductances of up to 5000 S/m. Given the high on-state currents at yet large on/off ratios, our novel structures also show promise for use in artificial neural networks, where they could operate as memristive devices with sub 100 fJ energy usage.