Self-Assemblies and Properties of Side-On Picene Strips on a Monolayered CuO Film

Abstract

Thermally deposited picene (C22H14) molecules on a monolayered CuO film were grown at a Cu(110) self-assemble into side-on molecular strips extending along the [11̅0] direction, as revealed by scanning tunneling microscopy (STM). The picene molecules are closely stacked on and anchored to the Cu–O chains via their armchair edges. They form two stacking modes and stick to the substrate via their long (Pic-I) and short (Pic-II) armchair edges. Such configurations are reversibly switchable by either an applied STM bias voltage pulse or continuous tip navigation. Scanning tunneling spectroscopies acquired above the Pic-I and Pic-II strips reveal different electronic states, showing a clear relationship between their electronic structures and their stacking modes on the substrate.