Imaging of charge transport properties in polycrystalline CVD diamond using IBIC and IBIL microscopy

Ion beam induced charge (IBIC) and ion beam induced luminescence (IBIL) res ults of polycrystalline CVD diamond radiation detectors are presented. Thes e detectors were designed as alpha particle and UV sensors, and were constr ucted with a coplanar electrode structure, fabricated only on the growth si de of the diamond film. IBIC results show the different efficiencies of ind ividual 10-20 mum wide grains at facilitating charge transport at different locations away from the surface metallisation. IBIL results show that some of the large grains which exhibit poor charge collection give a high lumin escence yield, whereas other regions exhibit both a low IBIC and IBIL signa ls. These results directly show that the charge collection efficiency in th e inter-electrode region is limited both by the size of the diamond crystal lites and also by the high luminescence yield of certain grains. (C) 2001 E lsevier Science B.V. All rights reserved.