Variations on the use of ion beam luminescence

Abstract

Luminescence excited during ion beam bombardment offers information on both stable and metastable defect and impurity sites, and it is a sensitive and powerful analytical tool for insulating materials and semiconductors. Most studies so far have focused on visible and UV emission spectra as the spectra reveal information on the formation and types of defect sites. The modifications are dependent on ionisation density, and synergistic effects with nuclear collision damage. There is thus the ability to track defect production and amorphisation of crystalline hosts. Further, ion beam excited luminescence is equally a useful probe for studying nanoparticle growth. Such data can be obtained at different implantation temperatures or combined with other thermal treatments. Pulsed ion beams have the potential to reveal variations in defect formation by lifetime resolution of the signals. However, there is far greater analytical potential which has not been widely developed. The current article will describe how to extend the effects of lifetime resolution; to detect phase transitions, both stable and transient; and the opportunities which arise from combining the ion beam induced luminescence signals with simultaneous excitation of the materials with photons, electrons or X-rays. The combination of two methods can differ from the sum of separate excitation irradiations and so offer details on metastable structures related to ion implantation. Site specific probes using rare earth doped materials during implantation to form laser waveguide structures can track relaxations of both the guide and boundary regions. The measurement of ion beam luminescence spectra and lifetime data over a wide temperature range have historically been under exploited. Parallel data from optical absorption taken during implantation can be similarly informative. Benefits from all such measurements will be discussed.