Microscopic structure and energy transfer of vacancy-related defect pairs with Erbium in wide-gap semiconductors

A. Konopka, S. Greulich-Weber, V. Dierolf, H. X. Jiang, U. Gerstmann, E. Rauls, S. Sanna, W. G. Schmidt

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Electron Paramagnetic Resonance (EPR) measurements of Erbium-doped 6H-SiC and wurtzite GaN samples are compared to total energy calculations based on density functional theory (DFT) in order to investigate the well-known luminescence of the intra 4f-shell transition at 1540 nm, useful in light-emitting diodes or lasers. The highly correlated f-electrons of Erbium (Er) have been treated within an LDA+U approach. We discus how pairs of an Er-ion with intrinsic defects can be responsible in GaN and SiC for relaxing the selection rules for intra 4f-shell transitions: In GaN our EPR investigation indicates the presence of a nitrogen vacancy next to the Er-ion. Through controlled generation of intrinsic defects in 6H-SiC single crystals and EPR measurements we support the corresponding model in SiC, that predicts defect pairs of an Er-ion and a neighboring carbon vacancy. In other words, low-energy irradiation seems to be a promising way to enhance the Er-luminescence desired for device applications.

Original languageEnglish
Pages (from-to)1041-1044
Number of pages4
JournalOptical Materials
Volume33
Issue number7
DOIs
StatePublished - May 2011

Keywords

  • EPR
  • Erbium
  • GaN
  • SiC

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