Leakage current and charge transport mechanism in Poly(phenylene oxide)-Conductor Schottky bilayers

Abstract

Conductor-insulator (CI) bilayers are the cornerstone of understanding the leakage current and charge transport in insulator-based multilayer structures. Among several studies focused on the charge transport mechanism (CTM) in insulators, only a few have investigated it in insulating polymers. In this work, we study the leakage current and charge transport mechanism in the ultrathin insulating polymer poly (phenylene oxide) (PPO) utilizing two types of conducting electrodes as electron injectors, TiN and 3D carbon nanosheets (CNSs). We show that the CTM in PPO is dominated by Schottky emission, illustrating a low charge trap density. The leakage current study on PPO enables us to extract some of the key parameters of PPO, especially the Schottky barrier height and polymer dielectric constant. The dominance of the Schottky mechanism sheds light on the CTM similarities between PPO and many high-k nonorganic insulators, which is promising for integrating this polymer into many microelectronic devices.