ION BEAM INDUCED LUMINESCENCE MAPS IN CVD DIAMOND AS OBTAINED BY COINCIDENCE MEASUREMENTS

A new theory is presented concerning both IBIC ( Ion Beam Induced Charge ) and IBIL ( Ion Beam Induced Luminescence ) as obtained by a few MeV ion microbeam of few micrometers spot size. The theory evidences the fact that IBIL depends on the ratio between the total carrier lifetime and the radiative recombination lifetime. The IBIL/IBIC maps, as obtained by dividing the two average signals pixel by pixel, depend only on radiative lifetime. IBIL maps, as obtained by coincidence measurements in order to avoid electric noise and to display also regions of low luminescence, as compared to IBIC maps, indicate for the first time that regions of long collection length and regions of strong radiative recombinations are the most important ones in CVD diamond. As a conclusion, recombination in CVD diamond seems to be mainly radiative.