Decay channels of Al L sub 2,3 excitons and the absence of O K excitons in. alpha. -Al sub 2 O sub 3

Journal Article · Sun Dec 15 04:00:00 EST 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.13277· OSTI ID:5574982

O'Brien, W L; Jia, J; Dong, Q; Callcott, T A ^[1]; Mueller, D L; Ederer, D L ^[2]; Shinn, N D ^[3]; Woronick, S C ^[4]

---

1. University of Tennessee, Knoxville, Tennessee 37996 (United States)
2. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
3. Division 1114, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
4. Cornell University, Ithaca, New York 14850 (United States)

The Al {ital L}{sub 2,3} and O {ital K} thresholds for single-crystal {alpha}-Al{sub 2}O{sub 3} have been studied by photoemission. Energy-distribution curves, constant-initial-state (CIS), and constant-final-state (CFS) spectra are reported and compared to the absorption spectrum reported previously. An exciton appears as a doublet at threshold in the Al {ital L}{sub 2,3} CFS, CIS, and absorption spectra. The details of the Al {ital L}{sub 2,3} CFS spectrum and absorption spectrum are similar, while the exciton is the only feature present in the CIS spectrum. Comparisons of the various Al {ital L}{sub 2,3} spectra allow the probabilities of different exciton decay channels to be determined. The probability for nonradiative direct recombination of the exciton is found to be (8{plus minus}1)% and the probability for Auger decay of the exciton is found to be (72{plus minus}20)%. Comparisons of the O {ital K} CIS and CFS spectra suggest that no O {ital K} exciton is formed.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5574982
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:24; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ABSORPTION SPECTRA
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CRYSTALS
DECAY
EMISSION
ENERGY-LEVEL DENSITY
EXCITONS
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHOTOEMISSION
QUASI PARTICLES
RECOMBINATION
SECONDARY EMISSION
SPECTRA