Flexible X-ray Imaging and Stable Information Storage of SrF<sub>2</sub>:Eu Based on Radio-Photoluminescence
Yucheng Li, Xuechun Yang, Xuechun Yang, Kuan Ren, Yulin Liu, Xu Zhan, Feng He, Keli Deng, Bo Deng, Wanli Shang, Jianjun Dong, Feng Wang, Qianli Li, Xuyong Yang, Xuyong Yang
Abstract
X-ray imaging has garnered widespread interest in biomedical diagnosis and nondestructive detection. The exploration of radio-photoluminescence has hastened the advancement of X-ray information storage. However, significant challenges persist in achieving the prolonged imaging of curved objects without attenuation. Here, europium-doped strontium fluoride (SrF 2:Eu) is meticulously created to exhibit a linear response to an extensive range of X-ray doses (maximum dose > 5000 Gy), showcasing excellent X-ray information reading/erasing reusability properties (10 cycles). This is accompanied by a red-to-blue emission transition under UV excitation, sustaining for 150 days without attenuation. To elucidate the phenomena of irradiated photoluminescent discoloration and the reversible X-ray storage of SrF 2:Eu, we propose an electron-vacancy trap (valence conversion) mechanism, information stably retained by the SrF 2:Eu-based device under ambient conditions due to high energy barriers. The time-lapse readout capability is further demonstrated for three-dimensional imaging of curved objects (10 lp mm –1 ) based on SrF 2:Eu embedded within a polydimethylsiloxane (SrF 2:Eu@PDMS). The SrF 2:Eu demonstrates time-lapse imaging, reversible radio-photoluminescence, and recoverable X-ray storage, offering a promising avenue for optical information encryption and anticounterfeiting applications.