We have performed ab initio pseudopotential density-functional calculations to study spatial distributions of potassium atoms in expanded K3 C60 monolayers and their effects on the conduction bands from the C60 's lowest unoccupied molecular orbitals (LUMOs). Our results show that, as the lattice constant a of the monolayer increases, the lowest-energy configuration for the potassium atoms changes from a honeycomb (a<10.8 Å) to a kagome lattice (a>11.4 Å), with an intermediate phase appearing in between. The calculated electronic structures show that the C60 -LUMO-derived conduction bands are deformed sensitively by the presence and location of the dopants in the intermediate and the kagome-lattice phases, deviating greatly from the rigid-band picture. The sensitivity to the dopants may provide a method for tailoring the C60 -derived electronic structures.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2008 Mar 12|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics