Positron lifetime results obtained under high-power steady-state and transient optical excitation were reported, and a model for analysing the results was presented. The method was applied to vacancy clusters in natural diamond, for which opto-electronic constants such as optical absorption cross-section and hole recombination cross-section were self-consistently analysed. The temperature dependences of transient and steady-state measurements were studied, suggesting the possibility of analysing the positron trapping to extended defects and vacancy clusters in semiconductors.

Positron Lifetime Spectroscopy with Optical Excitation: a Case Study of Natural Diamond. J.M.Mäki, T.Kuittinen, E.Korhonen, F.Tuomisto: New Journal of Physics, 2012, 14[3], 035023