d2 ion-doped vacancy-ordered double perovskites as broadband NIR scintillators for radiation detection

Abstract

Scintillators can convert high-energy X-rays into more easily observable visible-near-infrared (NIR) light, thus showing great application potential in fields such as medical imaging, industrial inspection, and high-energy physics. Current NIR photodiodes exhibit higher photoelectric conversion efficiency than their counterparts operating in the visible light region. Integrating NIR scintillators with NIR optoelectronic conversion devices exhibiting high photoelectric conversion efficiency represents a promising solution for achieving efficient X-ray detection. However, almost all current scintillators are limited to the visible light region or exhibit poor performance. In this work, we achieve efficient NIR scintillation by doping Cs₂ZrCl₆ with d² ions. The light yield (LY) of the sample is as high as 51 613 photons MeV⁻¹, and the detection limit is as low as 192 nGy_air s⁻¹. The flexible scintillator film with an area of 10 × 10 cm² prepared by combining the sample with PDMS can be successfully applied to X-ray imaging. The spatial resolution of the Cs₂ZrCl₆:Mo⁴⁺@PDMS scintillator screen was 10 lp mm⁻¹, determined using standard X-ray resolution test panel imaging and MTF = 0.2. This work demonstrates that vacancy-ordered double perovskite is a promising matrix for scintillators and a class of potential optically functional materials.