Polydopamine–Copper Hybrid Films as Source and Drain for Oxide Semiconductor Field‐Effect Transistors

Abstract Oxide semiconductors are one of the key components for flexible and transparent electronics, but their use has been limited by the work function of contact materials. Carbon‐based materials are strong candidates for flexible transparent electrodes, and nitrogen‐doped carbon materials have been specifically investigated due to the controllability of their work function. Of the many methods to dop nitrogen, the pyrolysis of biomolecules is a particular focus since it is a simple, inexpensive process that yields a high atomic percent of nitrogen. Polydopamine (pDop), which is inspired by adhesive proteins in mussels, has been suggested for use as a precursor for pyrolysis, and the pyrolyzed pDop–Cu hybrid film shows the lowest resistivity (1.4 × 10−4 Ω cm) in pyrolyzed carbon so far, for which copper chelation is attributed to reduction in resistivity. The pyrolyzed film also shows…