Fig. 1. (a) Schematic illustration of the mechanism of X-ray-irradiated luminescence for organic scintillators. (b) Chemical structures of copolymers P1 to P6.

Fig. 2. (a) The PL and delayed PL spectra of polymers P1 to P6 in the solid state at room temperature (excitation at 400 nm). (b) Phosphorescence decay curves of P1 to P6 in the solid state at room temperature (excitation at 400 nm). (c) Calculated energy diagram and spin-orbital coupling (ξ) of M1 monomer.

Fig. 3. (a) The X-ray absorption spectra of the M1 and acrylic acid monomers. (b) PXRD patterns of the copolymers P1 to P6. (c) Normalized RL spectra and the related photographs of P1 to P6 under X-ray irradiation. (d) RL intensity changes of P1 to P6 under the same X-ray irradiation condition. (e) The photostability of P2 at 510 nm for continuous X-ray irradiation dosage of 27.35 Gy. (f) LOD (defined as an SNR of 3) and linear behaviors of P2 and anthracene under low-dose-rate X-ray excitation.

Fig. 4. (a) Chemical structures of P7 and P8. (b) RL spectra of P2, P6, P7, and P8 under X-ray irradiation. (c) CIE chromaticity coordinate diagram of the RL of P2, P6, P7, and P8.

Fig. 5. (a) Photographs of a scintillator screen under daylight and X-ray irradiation. (b) MTF curve of the P2 scintillator screen. (c) Photograph and X-ray image of the standard X-ray test. Bright field and X-ray images of (d) a metallic spring in capsule and (e) a chip card using P2 scintillator screen. X-ray tube voltage, 50 kV; dose rate, 20mGys−1; exposure, 15 s.