Earlier Thermal Donors - O_i to TD3

Unfortunately these results are not sufficient alone to determine whether the 4 O_i di-y-lid is TD2 or TD3. There are then at least two possible schemes that could describe the early thermal donor family consistent with these results. The following section details these, and attempts to select one using further experimental data . We first present a scheme where the di-y-lid is TD2 and show that this contradicts experimental evidence. We then propose a scheme where the di-y-lid is TD3 and show that this may agree with the experimental data.

In this discussion a few things are assumed. Firstly that the trimer, O_3i is responsible for the 1006 cm^-1 absorption line, for the reasons discussed in Chapter 6. Secondly that the experimental data concerning the inactive form of TD1 and TD2 is correct [239], and these defects are isomers of one another. Finally we make use of the fact that TD3 is the primary thermal donor species observed in annealing studies. As discussed in Chapter 6, kinetic analysis by Markevich et al suggests the trimer is mobile [269].