Emission channeling studies of Li in semiconductors

The emission channeling and blocking technique is a direct method for lattice location of radioactive atoms in single crystals. In the case of alpha-emitting isotopes, position-sensitive detection of emitted particles has provided an efficient means of carrying out a large number of experiments, and Monte Carlo simulations of the channeling effect allow for rather accurate identification and quantitative determination of occupied lattice sites. This work reviews recent results on the lattice sites of Li in elemental and III-V semiconductors, including Si, GaAs, GaP, InP and InSb, obtained by emission channeling and blocking following ion implantation of Li-8 at temperatures between 30 and 700 K. Relevant properties of Li in these semiconductors are also briefly reviewed, and emission channeling and blocking is discussed in relation to other experimental methods which give direct information on lattice sites and atomic configurations of defects in semiconductors. The experimental methods described in this work are also suitable to study other probe-atom-host-crystal systems (possible examples are Li and Na in II-VI semiconductors or diamond, Er and other rare-earth elements in semiconductors or metals, etc.) and an outlook on ongoing and future experiments is given.