Temperature-dependent hole detrapping for unprimed polycrystalline chemical vapor deposited diamond

Rise-time distribution spectra of a polycrystalline chemical vapor deposited diamond detector were directly measured from alpha-particle induced pulse shapes over a temperature range of 240–280K. Pulses due to hole-dominated charge transport showed a strong delayed component due to thermal detrapping of charge from a shallow level, with a mean rise time that decreased strongly with increasing temperature. The activation energy of this shallow hole trap was directly measured using an Arrhenius plot, with a value of 0.31±0.03eV. No priming or pre-irradiation of the device was required in order to observe thermal detrapping, indicating that the concentration of shallow hole traps in this sample is relatively high. In contrast, no delayed component was observed from electron transport, indicating that only deep electron-trapping levels are active.