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

Abstract

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/<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>), a high specific sensitivity of <inline-formula> <tex-math notation="LaTeX">$41.441~\mu \text{C}$ </tex-math></inline-formula>/Gy<inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>mm³ and a linearity coefficient of 1.027 &#x00B1; 0.009 (1.011 &#x00B1; 0.001 at 0.16 V/<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>) in X-ray dose detection when biased at 0.66V/<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>. Furthermore, the optimal energy resolution of 0.76&#x0025; to ²⁴³Am-²⁴⁴Cm dual <inline-formula> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula>-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&#x0025; at 0.66V/<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> and 0.759&#x0025; at 0.16 V/<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>, respectively. These results show that this DRD has a great potential for accurate and sensitive detection in medical application.