Absorption spectra of germanium nanocrystals

✍ Scribed by Dmitriy V. Melnikov; James R. Chelikowsky

• Book ID: 104166234
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 128 KB
• Volume: 127
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/s0038-1098(03)00445-9

✦ Synopsis

Absorption spectra of hydrogenated germanium nanocrystals are calculated in real space using ab initio pseudopotentials constructed within the local density approximation. Nanocrystals with over 800 atoms are considered. We find the calculated spectra are essentially bulk-like for systems with , 250 atoms or more. The energy positions for the E 1 and E 2 reflectivity peaks are blue-shifted with respect to their bulk values owing to quantum confinement. Comparisons with available experimental data reveal good agreement for the energies of the E 1 peak, whereas the energy position of the E 2 peak is underestimated by a constant shift, which is independent of the nanocrystal size. This shift is consistent with local density calculations for bulk germanium.