Thermally stimulated current investigations on diamond x-ray detectors

Natural II-a type diamond is increasingly used for the fabrication of radia tion detectors. However, the presence of inherent defects has a strong impa ct on the detector characteristics such as the time-dependent stability of the detection signal. In order to draw better insight into this effect, com parative investigations of the x-ray responses with thermally stimulated cu rrent (TSC) measurements were carried out on natural diamond detectors. TSC revealed the presence of four peaks or shoulders on natural samples in the 200-500 K domain. Three energy levels were identified at about 0.7, 0.71, and 0.95 eV. Time-dependent x-ray detector sensitivity was investigated for various initial conditions. The results give evidence of the improvement o f the detection properties after having filled traps in the material by x-r ay irradiation. The comparison between the x-ray response and the TSC spect ra indicates that trapping levels emptied at room temperature appear to sig nificantly affect the performance of radiation detectors. (C) 2000 American Institute of Physics. [S0021-8979(00)06706-2].