X-ray absorption and photoemission spectra have been used to measure the band edges of silicon nanocrystals with average diameters ranging from 1 to 5 nm. We compare the experimentally measured band edges to recent electronic structure calculations and find that the experimentally measured band gap is smaller than that predicted by theory.

• Received 31 October 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.3803