Diamond film based detectors

Synthetic diamond films have been used to fabricate both particle and UV-radiation detectors. A CH4-CO2 gas mixture was used as a gas feed during the chemical vapor deposition (CVD) growth process. Film morphology, preferential orientation and crystal quality were systematically changed by varying the deposition parameters. In particular, the substrate temperature, Ts, and the CH4 concentration in the gas mixture were varied from 750°C to 850°C and from 47% to 50%, respectively. The resulting films were characterized by X-ray diffraction, scanning electron microscopy and cathodoluminescence spectroscopy (CL). The correlation of the above structural properties with the response of the diamond-based detectors was studied extensively. To this purpose, the detectors were irradiated with alpha particles from a 5.5 MeV241Am source and illuminated by a UV deuterium lamp, under different applied electric fields. Then, their collection lengths and efficiencies were compared.