Oxygen-related defects

Significant stimulated emission is only found for the pristine side of the sample. From these results it was concluded that the photoinduccd absorption that suppresses die stimulated emission is directly or indirectly caused by the presence of oxygen-related defects. It was shown earlier that the effect of photooxidation on the emission properties of PPV can be explained by the formation of carbonyl-groups that act as sLrong electron acceptors leading to an efficient dissociation of the plioh excited slate 29). It can be concluded that the dissociated pair near the defcci leads to the strong photoinduccd absorption. The observation that... 

Figure 9.15 Oxygen-related defects, whose radiative recombination provides the UV emission band in AIN.

Falster R, Fisher GR, Ferrero G (1991) Gettering thresholds for transition metals by oxygen-related defects in silicon. Appl Phys Lett 59 809... 

Figure 15 Schematic representation of the oxygen-related defect evolution as a function of oxygen content (a) region I-isolated aluminum vacancy with associated oxygen, (b) region 11-aluminum octahe-drally coordinated to oxygen, and (c) extended defect-an inversion domain boundary consisting of aluminum atoms octahedraUy coordinated to oxygen at the boundary (26).

RA Youngman, JH Harris. Luminescence studies of oxygen-related defects in aluminum nitride. J Am Ceram Soc 73(11) 3238-3246 (1990). 

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