Ultrashort 15-nm flexible radio frequency ITO transistors enduring mechanical and temperature stress

Abstract

Flexible radio frequency (RF) transistors play an important role in the fast-growing wearable smart sensors for data communication. However, the scaling capability and high-speed performance of the flexible transistor are far below the counterparts on rigid substrates, impeding the gigahertz high-speed applications. Here, we address the scaling and performance bottlenecks in flexible transistors by demonstrating natively flexible RF indium tin oxide transistors with deeply scaled 15-nm-long channel, capable of operating in the 10-GHz frequency range. The record-high cutoff frequency of 11.8 GHz and maximum oscillation frequency of 15 GHz can rival those on rigid substrates. Furthermore, the robustness of flexible RF transistors was examined, capable of enduring heavy-duty 10,000 bending cycles at 1-mm radius and extreme thermal stress from cryogenic temperature of 4.3 K and high temperature of 380 K.

Biomimetic wafer-scale alignment of tellurium nanowires for high-mobility flexible and stretchable electronics

“…Nevertheless, their carrier mobilities are usually limited to ~1 cm 2 V −1 s −1 , fundamentally restricting their applications in high-frequency electronics ( 13 , 14 ). Low-dimensional inorganic semiconductors, such as single-walled carbon nanotubes (SWCNTs) ( 12 ), silicon nanowires ( 15 – 17 ), metal oxides ( 18 ), and metal chalcogenides ( 11 , 19 ), are intrinsically flexible owing to their nanoscale thicknesses and can even be made stretchable by structural designs via wavy ( 20 ), serpentine ( 21 ), mesh ( 22 ), and kirigami geometries ( 23 ), or wrinkling ( 24 ) and buckling ( 25 ) architectures. Despite their carrier mobilities exceeding ~10 cm 2 V −1 s −1 , they typically require high growth or processing temperatures incompatible with soft substrates for direct integration or necessitate laborious procedures to achieve monodisperse inks for regulated electronic performance ( 13 ).…”

Phhgraphene: An Anisotropic Dirac Material with Intrinsic Self-Doping Features and a Tunable Band Structure

“…In recent years, the rapid development of the next-generation wearable technology has captured significant attention, particularly in the realm of flexible wearable devices. , Graphene, characterized as a Dirac material with a layer thickness typically in the order of a few angstroms, demonstrates high intrinsic mobility, rendering it a promising material for flexible radio frequency transistors. , Among the materials required for flexible devices, two-dimensional Dirac materials have drawn considerable interest due to their unique electronic structure and fascinating mechanical properties (e.g., higher electron mobility and ballistic charge transport). However, graphene as the star material among two-dimensional Dirac cone materials has been proven the electronic structures hardly be turned or controlled both theoretically , and experimentally. , This limitation has greatly impeded the widespread application of graphene in flexible wearable devices.…”

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

“…In recent years, the rapid development of the metaverse, human-computer interaction, intelligent medical technology [1], and other industries has propelled the advancement of flexible electronic device and actuators. As the foundation of flexible devices, various functional materials that are flexible and even stretchable are emerging rapidly, among which the dielectric elastomers are widely investigated due to their essential role in constructing flexible sensors, circuit [2], transistors [3], and artificial muscle. For example, thermoplastic polyurethanes (TPU) is considered a crucial component of the flexible capacitor [4], which plays a vital role in pressure sensing [5] and displacement measurement.…”