Mapping of polarization and detrapping effects in synthetic single crystal chemical vapor deposited diamond by ion beam induced charge imaging

Abstract

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 ͑CVD͒ 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 ␣-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± 0.02 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.

Spectrometric Performances of Monocrystalline Artificial Diamond Detectors Operated at High Temperature

“…We mention that a similar result was already reported in [12] for a detector produced by the same company which provided us the diamond film. The temperature range investigated in [12] was from 0 C up to 30 C. However, the increase of electrical noise was clearly visible and measurable in the PHS spectra as function of temperature and for C noise increased steeply as well as the dead time. For C we observed the paralyses of the electronics chain with a sudden reduction of both peak area (Fig.…”

“…The latter has been associated to hole trapping-detrapping and it has been also observed a reduction of this slow component as temperature increases, indicating a more efficient trapping-detrapping process of holes at high temperature [11]. Responsible of these effects are relatively shallows traps identified by various authors [8], [12] to be in the energy range 0.29-0.39 eV. As reported in Section IV-B, such effects were not observed with our commercial SCD detector.…”

The effect of fast neutron irradiation on the performance of synthetic single crystal diamond particle detectors

“…For the evaluation of the charge collection efficiency (CCE), the devices were tested using the same set-up, electronics and calibration procedure as described by Lohstroh et al [21]. The samples are irradiated with non-collimated 241 Am α-particles (emission energy 5.48 MeV) in a vacuum chamber with a remaining pressure of less than 10 -1 mbar.…”

“…If (some of) the defect levels present in the material responsible for priming and polarisation behaviour re-emit the trapped charge carriers within time scales that are comparable to the timescales in which the data is acquired, then the incident dose rate in addition to the total dose, will affect the detector performance as well. Reliable re-emission of trapped charge carriers in diamond is usually achieved by heating the samples above 550 K [20], but can also be induced by visible illumination [21]. The mechanism behind the latter is still not very well understood so far.…”

Comparison of the x-ray spectroscopy response and charge transport properties of semi-insulating In/Al doped CdZnTe crystals

“…6͑a͒. The detrapping time ͑ D ͒ distribution is directly measured from the exponential decay of the slow transient wave forms of the charge pulses described by Lohstroh et al 14 The relationship between D and the trap activation energy E A is given by 15…”