Influence of electrical defects on diamond detection properties

Abstract

Abstract The remarkable properties of diamond, together with its radiation hardness, make it an attractive material for specific applications in X-rays and charged particle detection. Because electrically active defects are known to influence the detection properties, a thorough study of these defects is of great interest in order to improve the detector characteristics. In this work, the response of diamond devices to X-rays and alpha particles is investigated and the results are correlated with the presence of traps analysed using thermally stimulated current (TSC) methods. The results of TSC analysis on natural diamond have enabled the determination of the energy of three levels activated near room temperature at 0.7, 0.71 and 0.95 eV and of a main principal level on CVD diamond at 1.2 eV activated near 550 K. The comparative study of TSC measurements and time dependent X-ray sensitivity are investigated on natural diamonds. The results confirm the improvement of the detection properties after having filled deep trap levels, and show a detrimental effect of the trapping levels emptied at room temperature on the turn-off time of diamond. Further, the temperature dependence of the detector response under alpha particles was also investigated. Clearly, a temperature increase above a level activated at 375 K leads to the improvement of the detection properties.