Large-area plastic nanogap electronics enabled by adhesion lithography

James Semple,Donal D C Bradley,Gwenhivir Wyatt-Moon,Dimitra G Georgiadou,Francesca Bottacchi,Stephan Rossbauer,Thomas D Anthopoulos,Emre Yengel,Minho Yoon,Martyn A Mclachlan,Akmaral Seitkhan

doi:10.1038/s41528-018-0031-3

Abstract

Large-area manufacturing of flexible nanoscale electronics has long been sought by the printed electronics industry. However, the lack of a robust, reliable, high throughput and low-cost technique that is capable of delivering high-performance functional devices has hitherto hindered commercial exploitation. Herein we report on the extensive range of capabilities presented by adhesion lithography (a-Lith), an innovative patterning technique for the fabrication of coplanar nanogap electrodes with arbitrarily large aspect ratio. We use this technique to fabricate a plethora of nanoscale electronic devices based on symmetric and asymmetric coplanar electrodes separated by a nanogap < 15 nm. We show that functional devices including self-aligned-gate transistors, radio frequency diodes and rectifying circuits, multi-colour organic light-emitting nanodiodes and multilevel non-volatile memory devices, can be fabricated in a facile manner with minimum process complexity on a range of substrates. The compatibility of the formed nanogap electrodes with a wide range of solution processable semiconductors and substrate materials renders a-Lith highly attractive for the manufacturing of large-area nanoscale opto/electronics on arbitrary size and shape substrates.

Highlights

Nanogap electrodes have received significant attention during the last decades and several bottom–up and top–down nanotechnology approaches have been proposed to fabricate coplanar electrodes with a separation reaching atomic scale resolution.[1]
A-Lith fabricated electrodes combined with self-assembled monolayer (SAM)-based gate dielectrics have been employed to fabricate molybdenum disulphide (MoS2) fieldeffect transistors (FETs).[8,9,10]
We focus on the development of symmetric and asymmetric coplanar electrodes with inter-electrode distances of < 15 nm and arbitrarily large aspect ratios. This is demonstrated using a variety of different substrate materials and implemented for proof-of-concept devices, including self-aligned-gate (SAG) metal oxide transistors, radio frequency (RF) diodes, nanoscale organic light-emitting diodes and non-volatile memory cells

Summary

INTRODUCTION

Nanogap electrodes have received significant attention during the last decades and several bottom–up and top–down nanotechnology approaches have been proposed to fabricate coplanar electrodes with a separation reaching atomic scale resolution.[1]. We have recently introduced adhesion lithography (a-Lith) as an alternative, scalable, low-temperature, and large-area patterning technique for the fabrication of sub-15 nm coplanar symmetric or asymmetric electrodes.[2] A-Lith is based on the modification of adhesion forces between two metals, one of which is functionalised with a suitable self-assembled monolayer (SAM). We focus on the development of symmetric and asymmetric coplanar electrodes with inter-electrode distances of < 15 nm and arbitrarily large aspect ratios. This is demonstrated using a variety of different substrate materials and implemented for proof-of-concept devices, including self-aligned-gate (SAG) metal oxide transistors, radio frequency (RF) diodes, nanoscale organic light-emitting diodes (nano-LEDs) and non-volatile memory cells. The present work highlights the tremendous versatility and adaptability of a-Lith to different devices of technological interest and demonstrates how it can be tailored to satisfy the electrode and substrate material, size and shape requirements posed by targeted applications

RESULTS

DISCUSSION

METHODS