Abstract
For pt.I see ibid., vol.13, no.3, p.359 (1980). A simplified version of a recent model for deep traps in semiconductors is used to derive the optical cross sections near threshold. It is found that the properties of the impurity and the host semiconductor band structure combine to give four basic functional forms. These theoretical cross sections are sufficiently different in their functional forms to allow an experimental distinction and hence the possibility of extracting some of the properties of the impurity involved.