Portable and Visualized X-ray Dose Rate Detection and Imaging Utilizing Br-Doped CsCdCl₃ Crystals

X-ray detectors are widely used for nondestructive detection in our daily lives, industries, and scientific studies. While their development has seen significant progress, the detection of radiation dose rates still requires expensive equipment and complex calibration procedures. Herein, we introduce a portable and visualized self-calibrated real-time X-ray dose rate detector based on Br-doped CsCdCl₃ crystals. This material exhibits a dual-emission band originating from two different self-trapped exciton recombination pathways. Importantly, Br-doped CsCdCl₃ crystals also exhibit a dual radioluminescence response under X-ray excitation. When the X-ray dose rate increases, the radioluminescence intensity at 480 nm increases at the expense of the peak at 595 nm. Based on the radioluminescence intensity ratio at these two wavelengths, a self-calibrated X-ray dose rate detector is constructed, which delivers a high relative sensitivity of 6% (mGy_air s^-1)^-1 at 0.6 mGy_air s^-1. Moreover, we have successfully achieved real-time visualization of X-ray dose rates by extracting color coordinates from photographs of luminescent Br-doped CsCdCl₃ crystals captured by a smartphone. Finally, we also demonstrated the application of Br-doped CsCdCl₃ powders embedded into a flexible polymer film for simultaneous X-ray imaging and dose rate detection.