Abstract
We have used time-resolved soft x-ray spectroscopy to investigate the electronic structure of optically excited cuprous oxide at the edge and the edge. The 400 nm optical excitation shifts the Cu and O absorptions to lower energy, but does not change the integrated x-ray absorption significantly for either edge. The constant integrated x-ray absorption cross-section indicates that the conduction-band and valence-band edges have very similar and orbital contributions. The 2.1 eV optical band gap of significantly exceeds the one eV shift in the - and -edges absorption edges induced by optical excitation, demonstrating the importance of core-hole excitonic effects and valence electron screening in the x-ray absorption process.
- Received 1 May 2009
DOI:https://doi.org/10.1103/PhysRevB.80.125210
©2009 American Physical Society