Electronic structure of pristine and K-doped solid picene: Non-rigid-band change and its implication for electron-intramolecular-vibration interaction

TL;DR

This study investigates the electronic structure changes in pristine and potassium-doped solid picene using photoemission spectroscopy, revealing non-rigid-band behavior and the significance of electron-intramolecular-vibration interactions in the doping process.

Contribution

It demonstrates that K-doped picene's electronic structure cannot be explained by a simple rigid-band model, highlighting the role of electron-intramolecular-vibration interactions through combined experimental and theoretical analysis.

Findings

K-doped picene shows new states near the Fermi level.

The electronic structure change cannot be explained by a rigid-band model.

Electron-intramolecular-vibration interaction is crucial in K-doped picene.

Abstract

We use photoemission spectroscopy to study electronic structures of pristine and K-doped solid picene. The valence band spectrum of pristine picene consists of three main features with no state at the Fermi level (EF), while that of K-doped picene has three structures similar to those of pristine picene with new states near EF, consistent with the semiconductor-metal transition. The K-induced change cannot be explained with a simple rigid-band model of pristine picene, but can be interpreted by molecular orbital calculations considering electron-intramolecular-vibration interaction. Excellent agreement of the K-doped spectrum with the calculations points to importance of electron-intramolecular-vibration interaction in K-doped picene.