The Yellow Excitonic Series of Cu2O Revisited by Lyman Spectroscopy

TL;DR

This study observes and analyzes the yellow exciton Lyman series in Cu2O using time-resolved mid-infrared spectroscopy, providing detailed electronic structure information and confirming hydrogenic model predictions.

Contribution

It reports the first observation of the yellow exciton Lyman series up to the fourth term in Cu2O and extracts key electronic parameters using a refined hydrogenic model.

Findings

Observation of the Lyman series up to n=4 in Cu2O

Determination of the 1s exciton Bohr radius as 7.9 Å

Measurement of the 1s-2p transition dipole moment as 4.2 eÅ

Abstract

We 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 the 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 a_{1s}=7.9 A and a 1s-2p transition dipole moment \mu_{1s-2p}= 4.2 eA were found.