High‐Throughput Fabrication of Flexible and Transparent All‐Carbon Nanotube Electronics

Abstract

This study reports a simple and effective technique for the high‐throughput fabrication of flexible all‐carbon nanotube (CNT) electronics using a photosensitive dry film instead of traditional liquid photoresists. A 10 in. sized photosensitive dry film is laminated onto a flexible substrate by a roll‐to‐roll technology, and a 5 µm pattern resolution of the resulting CNT films is achieved for the construction of flexible and transparent all‐CNT thin‐film transistors (TFTs) and integrated circuits. The fabricated TFTs exhibit a desirable electrical performance including an on–off current ratio of more than 105, a carrier mobility of 33 cm2 V−1 s−1, and a small hysteresis. The standard deviations of on‐current and mobility are, respectively, 5% and 2% of the average value, demonstrating the excellent reproducibility and uniformity of the devices, which allows constructing a large noise margin inverter circuit with a voltage gain of 30. This study indicates that a photosensitive dry film is very promising for the low‐cost, fast, reliable, and scalable fabrication of flexible and transparent CNT‐based integrated circuits, and opens up opportunities for future high‐throughput CNT‐based printed electronics.

The Evolution of Flexible Electronics: From Nature, Beyond Nature, and To Nature

“…[67][68][69][70][71][72][73] For instance, carbon nanotubes (CNTs) are widely employed in microelectronics [74][75][76] and energy storage [77][78] fields for their superior mechanical strength and excellent electric properties. [79][80][81] Zinc oxide (ZnO) with a wide band gap (3.37 eV) as well as distinct electrical, catalytic, and optical properties plays a vital role in sensing, [82] energy storage, [83] dielectric properties, [84,85] photodetecting, [86] etc. However, innovative structural designs for these functional materials should be adopted for the construction of flexible electronic devices in order to sustain in various mechanical strain/stress environments and meanwhile remain or even improve their performances.…”

Chirality‐Enriched Carbon Nanotubes for Next‐Generation Computing

“…[64] Other studies have demonstrated shape-controlled substrates, [65] intrinsically stretchable transistors, [66] and highthroughput fabrication using a photosensitive dry film. [67] In shape-controlled substrates, SWCNT flexible electronic devices are fabricated on a bilayer of polyimide and a shape memory polystyrene structure. These structures are formed into freestanding 3D shapes through structural pre-programming, and can also conformably wrap around irregularly shaped objects through rapid heating.…”

“…TFTs and inverters fabricated with this scheme have attained high performance, reproducibility, and uniformity over the entire PEN substrate, highlighting the potential of this manufacturing technique in future low-cost, R2R fabrication of SWCNT computational devices. [67]…”

Recent Progress in Inkjet‐Printed Thin‐Film Transistors

“…In particular, the ability to realize flexible thin‐film transistors (TFTs), which are key driving/switching component of wearable electronics, offers much freedom on the target substrates. Therefore, a variety of functional materials focusing on semiconductors have been extensively explored for realizing competitive flexible TFTs, including traditional silicon, organics, oxides, carbon nanotubes (CNTs), and emerging 2D materials . Furthermore, because representative flexible or stretchable platforms, such as polymer‐based plastic and polydimethylsiloxane (PDMS) substrates, are difficult to utilize in traditional microfabrication, the development of alternative processes that can be employed for implementing low‐cost, large‐area, flexible, and biocompatible electronics is key to meet this demand.…”