Fig. 5.

a Signal-to-noise ratio of the device derived by calculating the standard deviation of the X-ray photocurrent. The red dashed line represents a SNR of 3, and thus the detection limit is 59.7 nGyair s⁻¹ at 5 V bias, as indicated by the purple star surrounded by the red dashed circle. b Operational stability of our Cs₂AgBiBr₆ single-crystal X-ray detector. Testing conditions: continued 138.7 μGyair s⁻¹ X-ray irradiation with constant 5 V bias, tested in ambient air without any encapsulation. Reproduced with permission from Ref. [54]. c Transient responses of the detector at a constant 400 V. Reproduced with permission [92]. d The generated voltage of multiplier tubes by scintillation light of Cs₂NaTbCl₆ (red line), Cs₂NaEuCl₆ (blue line) and (Lu,Y)₂SiO₅:Ce³⁺ (LYSO, black line), respectively (color online). Reproduced with permission from Ref. [93]. (Color figure online)