Improving the Electrical Characteristics of Pentacene Organic Field Effect Transistors with Low-Cost Copper Electrodes by Self-Assembled Monolayer Modification

This work explored the possibility to tune the properties of the metal-semiconductor interface in organic field-effect transistors (OFETs) through insertion of 2,3,4,5,6-Pentafluorothiophenol (PFBT) and octadecyl phosphonic acid (ODPA) self-assembled monolayer on the metal-organic and dielectric organic interface of OFET respectively. The interfaces were modified with their respective self-assembled monolayers (SAMs) through immersion method and the modified surfaces were characterized with contact-angle measurements and atomic force microscopy measurements. Then, OFETs employing pentacene semiconductor with and without modified electrodes were fabricated and among them, the devices with PFBT modification demonstrated a superior operational parameter as opposed to as-prepared OFETs in terms of in saturation field-effect mobility going from 0.0002 to 0.0254 cm² V s^-1, and improvement in threshold voltage and on/off-current ratio.