Investigation of Chemical-Vapour-Deposition Diamond Alpha-Particle Detectors

Diamond films with 100 texture were prepared by a hot-filament chemical vapour deposition technique to fabricate particle detectors. The response of detectors to 5.5MeV²⁴¹Am particles is studied. The photocurrent increases linearly and then levels off with voltage, and 7nA is obtained at bias voltage of 100V. The time-dependent photocurrent initially increases rapidly and then tends to reach saturation. Furthermore, a little increase of the dark-current after irradiation can be accounted for by the release of the charges captured by the trapping centres at low energy levels during irradiation. An obvious peak of the pulse height distribution can be observed, associated with the energy of 5.5MeV.