A Large Gain and High Resolution Diamond Radiation Detector With Au/Hydrogen Termination Ohmic Contact

Diamond radiation detector (DRD) with high performance in dose detection and energy resolution is demonstrated in this letter. Benefiting from a good ohmic contact between hydrogen terminated diamond surface and Au, and very low defects in single crystal diamond, this DRD achieves a large current gain factor of 151.83 (349.93 at 1 V/ $\mu \text{m}$ ), a high specific sensitivity of $41.441~\mu \text{C}$ /Gy $\cdot $ mm³ and a linearity coefficient of 1.027 ± 0.009 (1.011 ± 0.001 at 0.16 V/ $\mu \text{m}$ ) in X-ray dose detection when biased at 0.66V/ $\mu \text{m}$ . Furthermore, the optimal energy resolution of 0.76% to ²⁴³Am-²⁴⁴Cm dual $\alpha $ -source is shown in hole collection mode at the same bias. Meanwhile, owing to none of priming effect and persistent photoconductivity in the device, the on-state current fluctuations of dynamic switching measurements under steady X-ray irradiation are 0.929% at 0.66V/ $\mu \text{m}$ and 0.759% at 0.16 V/ $\mu \text{m}$ , respectively. These results show that this DRD has a great potential for accurate and sensitive detection in medical application.