Induced Effect in ODMR

The nature of the conduction-band-tail states that are responsible for radiative recombination is not clear. Potential fluctuations occur at the conduction-band edge due to the disorder associated with the random network of Si atoms and the random distribution of foreign atoms such as H and F (Dunstan and Boulitrop, 1981). As a result, local minimum energy states are created, in which electrons are captured after band-to-band excitation. These states may be possible candidates for conduction-band-tail states. 

In Part IV, the A center is identified as a trapped hole state, but its detailed nature is also not clear. Although a three-center bond model has been proposed (Morigaki et al, 1980a), we think that the A center corresponds to the self-trapped hole state proposed by Tsang and Street (1979). 

According to a model of light-induced centers proposed by Hirabayashi et al. (1980), a dangling bond is created by breaking a Si - Si bond near a Si - H bond. However, experimental evidence for this model has not been obtained. 

The creation of dangling bonds stabilizes the atomic configuration by using the energy released by the nonradiative recombination (Morigaki et al, 1980b). 

---