High-Performance Fiber-Shaped Vertical Organic Electrochemical Transistors Patterned by Surface Photolithography

Abstract

Converging the fibrous flexibility and resilience with the advantageous electrical properties of organic electrochemical transistors (OECTs), fiber-shaped OECTs possess great potential in wearable electronics. However, limited by current highly recognized fabrication techniques for film devices, micrometer-scale patterning capability of electrodes and semiconductor channels on the curved surface of fibers is still challenging. In addition, the well-defined short channel length of fibershaped OECTs is highly desired to narrow the performance gap with planar OECT devices. In this study, the fabrication of photopatterned vertical OECT devices on fiber surfaces (fiber-shaped vOECTs) is achieved. Moreover, the first n-type fiber-shaped vOECTs and high-performance ptype fiber-shaped vOECTs are realized. The fiber-shaped vOECT devices work in enhancement mode, with remarkable maximum transconductance (p-type: 41.10 mS, n-type: 2.25 mS) and current on/off ratio (∼10 4 ), together with good cycling stability (maintaining over 90% of performance beyond 500 cycles). Furthermore, by using knitting and weaving fabric textures, complementary inverter, NAND and NOR logic gates integrated through fiber-shaped vOECTs are derived and showcased. This study demonstrates the potential of this approach as a universal platform for fabricating high-performance semiconductor devices.

Semiconductor fibers for textile integrated electronic systems

“…Traditional lithography technology typically involves coating a substrate with a light-sensitive photoresist, exposing it to ultraviolet (UV) light through a patterned mask, etching uncovered areas and stripping the photoresist to reveal a patterned substrate, which is mainly applicable to flat and rigid surfaces. To this end, a rotating lithography technology was developed to solve the processing issues of lithography on curved surfaces [ 5 , 6 ]. In a typical rotating lithography process, the outer surface of the cylindrical fiber is gradually scanned and patterned by a linear UV light source by controlling the axial rotation of the fiber.…”

“… (a) Lithography technology for semiconductor fibers. (I) Rotating lithography process for curved surface on fiber [ 5 , 6 ]. (II) Methods of lithography on profiled fibers [ 7 ].…”