Electronic Structure of Doped Polyparaphenylene

Abstract

Electron energy-loss spectroscopy has been used to investigate the electronic structure of n- and p-doped poly-paraphenylene. For low doping concentration evidence is found for the formation of bipolaron states in the gap. For Li doping at the highest doping level, the gap between bonding and anti-bonding π-electrons is closed and a metallic state is observed.