Electronic and structural coupling of pentacene on NiO(001)

Area of Science:

• Surface Science
• Materials Science
• Spintronics

Background:

• Transition-metal oxides (TMOs) are crucial for advanced applications.
• Antiferromagnetic TMOs show promise for spintronic devices.
• Interactions between TMOs and molecular layers are an active research area.

Purpose of the Study:

• Investigate pentacene adsorption on the NiO (001) surface.
• Determine molecular arrangement and energy level alignment.
• Explore potential for molecule-based functionalization of antiferromagnetic surfaces.

Main Methods:

• Scanning tunneling microscopy
• Low energy electron diffraction
• Angle-resolved photoelectron spectroscopy
• Density functional theory calculations

Main Results:

• Pentacene forms a self-assembled monolayer in a superstructure on NiO.
• Identified highest occupied molecular orbitals (HOMO, HOMO-1, HOMO-2) via photoemission.
• Negligible charge transfer observed at the interface.
• Induced degeneracy of HOMO-1 and HOMO-2 orbitals and electron density accumulation toward the substrate.

Conclusions:

• Pentacene preserves its frontier orbital electronic character on NiO.
• Potential for optical control of THz spin dynamics in antiferromagnetic NiO.
• Opens new avenues for engineering molecule-functionalized antiferromagnetic surfaces.