Channel length scaling of over 100% biaxially stretchable carbon nanotube transistors

Abstract

Deformable field effect transistors (FETs) are needed for future technologies such as stretchable electronics. We have previously integrated buckled networks of polymer-sorted semiconducting carbon nanotubes and buckled layers of an ion gel dielectric onto elastomeric substrates to create FETs with a channel length of 100 μm that are biaxially stretchable. However, the channel length scaling behavior of this type of FET has not yet been investigated. Of particular concern is the viability of this device architecture when the channel length is reduced below 10 μm, approaching the characteristic buckling length-scale. Here, we fabricate and test buckled nanotube FETs with channel lengths of 8, 17, and 31 μm. We find that the buckling length-scale decreases as the channel length is reduced and that devices at all channel lengths are viable, demonstrating a field-effect mobility of >5 cm2 V−1 s−1 and an on/off ratio of >104, with stability up to 100% biaxial elongation without degradation of performance. A biaxially stretchable inverter is also demonstrated. These findings are important because smaller and higher conductivity FETs that are deformable are needed for next-generation technologies such as stretchable, high-resolution displays and sensors.