Correlation and electron-phonon effects in the valence-band photoemission spectra of single-phaseK3C60films

Abstract

Ultraviolet photoemission spectroscopy is used to show that the density of states just below the Fermi edge of a high quality single-phase ${\mathrm{K}}_{3}{\mathrm{C}}_{60}$ film is significantly affected by temperature. In addition, the possible contribution of electron-phonon and electron-plasmon interactions, as well as of correlation effects to the lowest unoccupied molecular orbital derived photoemission spectrum is addressed by reproducing the experimental data starting from theoretical density of states reported in the literature and by comparison with the photoemission spectrum of a single-ordered layer of ${\mathrm{C}}_{60}$ on Ag(100).