High performance hydrogen/oxygen terminated CVD single crystal diamond radiation detector

We report the performance of a single crystal diamond radiation detector with gold films on hydrogen-terminated diamond as electrical contacts and oxygen-terminated diamond as surface isolation between electrodes. The origin-symmetric current-voltage characteristics showed excellent Ohmic contact behavior. An extremely low dark current value of 7.46 x 10(-13) A/mm(2) was measured at an electric field of 1 V/mu m. The charge collection efficiency and energy resolution of this detector were 99.01% and 1.5% for holes, and 98.6% and 1.7% for electrons under irradiation with Am-241 alpha-particles. Under Co-60 gamma-ray irradiation with a dose rate of 1.271 Gy/s, the gain factor, specific sensitivities, and signal-to-noise ratio were 49.46, 12.43 mu C/Gy center dot mm(3), and 1 x 10(6) at 200 V bias voltage (0.66 V/mu m), respectively. A rise time of 347.4 ps of the response to a pico-second pulsed electron source was also measured. This research provides a possibility to improve the performance of the diamond radiation detector through diamond surface modification.