The role of charge trapping at grain boundaries on charge transport in polycrystalline chemical vapor deposited diamond based detectors

Abstract

We report a detailed investigation of the trapping and release of charge carriers from grain boundaries in polycrystalline diamond grown by chemical vapor deposition (poly-CVD). A model for charge trapping and release is presented for samples which display very different bulk characteristics as determined by photoluminescence, dark conductivity, and thermally stimulated current measurements. Experimental studies were performed as a function of temperature and applied electric field using ion beam induced charge to map the charge collection efficiency of charge induced by a scanned, focused, 2 MeV He+ microprobe. Even though the carrier velocity and charge collection efficiency should begin t..