Preparation and electronic properties of potassium doped graphite single crystals

Abstract

Here we revisited the electronic structure of potassium doped graphite using angle-resolved photoemission spectroscopy (ARPES). We perform an analysis of the charge transfer from potassium to graphite employing a tight-binding model for the band structure. Our ARPES measurements clearly show that the π* band of graphite becomes occupied upon deposition and intercalation of small amounts of potassium. The observed shift in the Fermi level of ∼ 400 meV is well below the appearance of staged graphite compounds and is described by a rigid band shift model. The π* band in pristine graphite is unoccupied and can therefore not be measured by ARPES. Thus potassium doping in the dilute limit provides a key for measuring the π* bands close to the Fermi level by ARPES. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).