Defect luminescence in films containing Ge and GeO{sub 2} nanocrystals
Amorphous SiO{sub x} alloys containing Ge or GeO{sub 2} nanocrystals are produced by dc-magnetron sputtering and controlled crystallization. The samples are investigated by Raman scattering, transmission electron microscopy, photoluminescence and excitation spectroscopy. Under UV excitation, both types of films luminesce around 3.1 eV, with identical PL line shapes and subnanosecond PL dynamics. The strongest PL intensity is found for the films containing FeO{sub 2} crystals and for the largest nanocrystals. These results are a clear indication that although the blue luminescence is without a doubt correlated with the formation of Ge (or GeO{sub 2}) nanocrystals, it is not produced by the radiative recombination of excitons confined in the nanocrystals. Possible mechanisms for the luminescence are discussed, including defects at the nanocrystal/matric interface or in the matrix itself.
- Research Organization:
- Otto-v.-Guericke Univ., Magdeburg (DE)
- OSTI ID:
- 20085508
- Country of Publication:
- United States
- Language:
- English
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