We report the electron and hole charge transport properties of semi insulating CdTe:Cl grown by the Travelling Heater Method (THM). An alpha-particle Time of Flight (TOF) method was used to measure electron and hole drift mobility, with room temperature values of 880 cm² /Vs for electrons and 90 cm²/Vs for holes. The variation in mobility was also investigated as a function of temperature, with electron and hole mobilities at 190 K of 1150 cm² /Vs and 20 cm²/Vs respectively. Using a Hecht analysis the electron and hole mobility-lifetime products were also measured over the same temperature range, with values at room temperature of 8times10^-4 cm²/V and 7times10^-5 cm ²/V respectively. Time-resolved ion beam induced charge (IBIC) imaging was used to produce micrometer resolution maps of electron drift mobility and signal amplitude, which showed excellent spatial uniformity

The authors report correlations between variations in charge transport of electrons and holes in synthetic single crystal diamond and the presence of nitrogen impurities and dislocations. The spatial distribution of these defects was imaged using their characteristic luminescence emission and compared with maps of carrier drift length measured by ion beam induced charge imaging. The images indicate a reduction of electron and hole mobility–lifetime product due to nitrogen impurities and dislocations. Very good charge transport is achieved in selected regions where the dislocation density is minimal.

Diamond has been regarded as a promising radiation detector material for use as a solid state ionizing chamber for decades. The parameters degrading the charge transport from what is expected from an ideal crystal are still not completely understood. Recently, synthetic chemical vapor deposited (CVD) single crystal diamond has become available, offering the opportunity to study the properties of synthesized material independent of grain boundaries. We have studied the charge transport of a synthetic single crystal diamond with $\alpha$ -particle induced charge transients as a function of temperature and established the presence of a shallow hole trap with an activation energy of $0.29\pm 0.02\mathrm{eV}$ in some parts of the detector. Ion beam induced charge imaging has been used to study the spatial variations of the charge transport in a synthetic single crystal diamond. Pulses influenced by the shallow hole trap had their origin close to the substrate∕CVD interface of the sample. They could be clearly distinguished from pulses affected by reduced charge carrier velocities due to polarization phenomena, which varied systematically with the growth direction of the CVD diamond material.