Large-Area Electrode Deposition and Patterning for Monolayer Organic Field-Effect Transistors by Vacuum-Filtrated MXene

High-quality organic field-effect transistors (1L-OFETs) based on monolayers have made significant progress and are expected to be key components in the development of next-generation flexible electronics. However, a flexible, low-cost, damage-free, and metallic conductance electrode that can accurately demonstrate the exceptional electrical properties of 1L-OFETs is still in high demand. In this study, the vacuum-filtrated MXene (Ti₃C₂T_x) is demonstrated to serve as electrodes without causing chemical or thermal damage to the delicate active layer via a dry-lithography method. By integrating monolayer 2,9-didecyldinaphtho[2,3-b:2,3′-f]thieno[3,2-b]thiophene (C₁₀-DNTT) with MXene, the 1L-OFETs exhibit a low subthreshold swing of 60.7 mV per decade and high field-effect mobility of 9.5 cm² V⁻¹ s⁻¹ on a high-κ dielectric hafnium oxide. The use of MXene electrodes enables the production of solution-processed conductors that can achieve uncompromised performance compared to metal contacts. Furthermore, owing to the well-matched work functions, the contact resistance can be reduced to 165 Ω cm by this printing technique. The 1L-OFETs fabricated on an ultra-thin conformal parylene substrate also exhibit uniform electrical properties. It is believed that this processing approach of vacuum-filtrated MXene conductors is a crucial step toward the application of non-metal contacts for high-performance flexible electronics.