The Yellow Excitonic Series of Cu2O Revisited by Lyman Spectroscopy

International audienceWe report on the observation of the yellow exciton Lyman series up to the fourth term in Cu2O by time-resolved mid-infrared spectroscopy. The dependence of oscillator strength on the principal quantum number n can be well reproduced using the hydrogenic model including an AC dielectric constant, and precise information on the electronic structure of the 1s exciton state can be obtained. A Bohr radius a1s=7.9 Å and a 1s–2p transition dipole moment µ1s–2p=4.2 eÅ were found