Vibrational-mode theory of acceptor-hydrogen complexes in silicon

The vibrational properties of the acceptor-hydrogen complexes, for the acceptors B, Al, and Ga, in Si have been investigated within the framework of the Assali and Leite model proposed for the microscopic structure of the complexes [Phys. Rev. Lett. 55, 980 (1985)]. The $A_1$ and E vibrational modes of the complexes were studied by using a molecular cluster embedded in a rigid Si lattice, where H at an interstitial site is connected to its three Si and the acceptor nearest neighbors by spring force constants of variable strength. It is shown that the model reproduces all the vibrational energies of the hydrogen- and deuterium-related complexes measured so far. Indeed, the model is used to predict several new values of vibrational energies associated to these complexes.