Excitation mechanisms of multiple Er3+ sites in Er-Implanted GaN

S. Kim, S. J. Rhee, X. Li, J. J. Coleman, S. G. Bishop, P. B. Klein

Research output: Contribution to journalArticlepeer-review

Abstract

Site-selective photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies carried out at 6K on the ∼1540 nm 4I13/24I15/2 emissions of Er3+ in Er-implanted GaN have revealed the existence of four different Er3+ sites and associated PL spectra in this semiconductor. Three of these four sites are excited by below-gap, impurity- or defect-related absorption bands, with subsequent nonradiative energy transfer to the Er3+ 4f electrons; a fourth site is excited by direct Er3+ 4f shell absorption. PLE spectra obtained by selectively detecting Er3+ PL from each of the three sites pumped by broad below-gap absorption bands are compared with the PLE spectra of broad PL bands attributed to implantation damage-induced defects in the Er-implanted GaN. This comparison enables us to distinguish broad-band, below-gap optical excitation processes for Er3+ emission that are attributable to (1) absorption due to implantation damage-induced defects; (2) absorption due to defects or impurities characteristic of the as-grown GaN film; and (3) an Er-specific absorption band just below the band gap which may involve the formation of an Er-related isoelectronic trap. The two sites excited by impurity- or defect-related absorption bands are also strongly pumped by above-gap excitation, while the sites pumped by the Er-related trap and direct 4f shell absorption are not. This observation indicates that excitation of Er3+ luminescence in crystalline semiconductor hosts by either optical or electrical injection of electron-hole pairs is dominated by trap-mediated carrier capture and energy transfer processes. These trap-mediated processes may also control the thermal quenching of Er3+ emission in semiconductors.

Original languageEnglish (US)
Pages (from-to)246-254
Number of pages9
JournalJournal of Electronic Materials
Volume27
Issue number4
DOIs
StatePublished - Apr 1998

Keywords

  • Er-implantation
  • GaN
  • Photoluminescence

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Materials Science(all)
  • Electronic, Optical and Magnetic Materials
  • Physics and Astronomy (miscellaneous)

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