N‐Type Single Walled Carbon Nanotube Thin Film Transistors Using Green Tri‐Layer Polymer Dielectric

Abstract

Abstract The proliferation of disposable, wearable, and implantable printable electronics requires the development of high‐performance biodegradable, and sustainable electronic components. Often green materials don't have the necessary properties for high‐performance electronics, therefore obtaining the ideal properties requires a combination of multiple green materials. A tri‐layer dielectric is reported using poly(lactic acid) (PLA), poly(vinyl alcohol)/cellulose nanocrystals (PVAc), and toluene diisocyanate terminated poly(caprolactone) (TPCL), which is integrated into semiconducting single‐walled carbon nanotube (sc‐SWCNT) based thin film transistors (TFTs) in a top gate bottom contact architecture. The PVA provides a high dielectric constant due to the hydroxy groups, the cellulose is used to optimize the viscosity, the TPCL layer provides a robust hydrophobic surface, and the PLA eliminates the interfacial charge traps present in the PVAc and improves the adhesion between PVAc and the substrate. This leads to a decrease in leakage currents and reduces the polarity at the dielectric/semiconductor interface. The TFTs fabricated using tri‐layer dielectrics led to air‐stable n‐type devices with higher overall performance when compared against the PVAc/TPCL bilayer devices.

Keywords

• encapsulation
• green tri‐layer dielectric
• interface engineering
• n‐type
• single‐walled carbon nanotubes
• surface modification