Poly and Mono-Crystalline Synthetic Diamond Detectors
Diamond is intrinsically an insulating material, So its electric resistivity is very high and practically to current can flow spontaneously under applied electric fields also high, as of the order of more then 20 kV/cm. To induce electrical current under the action of an applied field it is necessary to allow the diamond to be crossed by ionizing particles, which can create along their path pairs of electrons and holes which can flow to anode and cathode respectively, giving rise to an electric pulse for each bombarding particle. The realization of diamond particle detector can be limited by the fact that diamond shows a non-negligible leakage of electrons or holes during their flow to electrodes. This leakage is caused by the intrinsic defects of the diamond crystals and it gives rise to reductions of the output electric pulses. [Figura_Diamond]
After a long investigation and various tests done in previous years, a suitable model of the electrical conduction of a polycrystalline synthetic CVD diamond under bombardment of ionizing particles has been developed. The same model has been then applied to mono-crystalline CVD synthetic diamonds to deduce the much less value of the crystalline defect density in these diamonds, concluding that the mismatch between silicon backing and diamond crystal parameters is the main cause for crystal defects. We can conclude (see Activity Reportpag. 82) that hopes for good spectroscopy detectors made of diamond lay on good technology for production of single crystal diamond films, that is diamond films grown on diamond itself as backing.
S. Albergo, V. Bellini, S. Costa, F. Mammoliti, R. Potenza, C. Sutera, A. Tricomi, C. Tuvè