Enhanced Performance of Self‐Assembled Monolayer Field‐Effect Transistors with Top‐Contact Geometry through Molecular Tailoring, Heated Assembly, and Thermal Annealing

Abstract

Low‐voltage self‐assembled monolayer field‐effect transistors (SAMFETs) that operate under an applied bias of less than −3 V and a high hole mobility of 10−2 cm2 V−1 s−1 are reported. A self‐assembled monolayer (SAM) with a quaterthiophene semiconducting core and a phosphonic acid binding group is used to fabricate SAMFETs on both high‐voltage (AlOx/300 nm SiO2) and low‐voltage (HfO2) dielectric platforms. High performance is achieved through enhanced SAM packing density via a heated assembly process and through improved electrical contact between SAM semiconductor and metal electrodes. Enhanced electrical contact is obtained by utilizing a functional methylthio head group combined with thermal annealing post gold source/drain electrode deposition to facilitate the interaction between SAM and electrode.