Hydrogen-acceptor pairs in silicon: Pairing effect on the hydrogen vibrational frequency

Abstract

We calculate the electronic structures of the hydrogen-boron and hydrogen-aluminum pairs in silicon which are believed to form when the corresponding shallow acceptor activity is neutralized by hydrogen. In particular, computed infrared vibrational frequencies are reported for the first time and compared with recent experimental measurements. Both theory and experiment reveal an interesting reduction in the vibrational frequency for hydrogen in the H-B pair with respect to the isolated monohydride. This we analyze in terms of two- and three-body interactions involving the hydrogen, the acceptor impurity, and the nearby silicon atoms.