Polycrystalline Lead-Free Perovskite Direct X-Ray Detectors with High Durability and Low Limit of Detection via Low-Temperature Coating

Abstract

Direct X-ray detectors represent a transformative technology in the realm of radiography and imaging. The double halide-based perovskite cesium silver bismuth bromide (Cs 2 AgBiBr 6 ) has emerged as a promising material for use in direct X-ray imaging, owing to its nontoxic composition, strong X-ray absorption, decent charge mobility lifetime product (μτ), and low-cost preparation. However, formidable issues related to scalability and ion migration, stemming from intrinsic factors such as halogen vacancies and grain boundaries, have presented significant impediments. These issues have been associated with substantial noise, baseline instability, and a curtailment of detection performance. In response to these multifaceted challenges, we propose a slurry-based in situ treatment technique for fabricating robust Cs 2 AgBiBr 6 thick films. This novel approach adeptly mitigates halogen vacancies, actively passivates grain boundaries, and concurrently elevates the ion migration activation energy, thus effectively suppressing ion migration. Consequently, the obtained X-ray detector exhibits excellent operating stability with minimal signal drift of 8.5 × 10 −9 nA cm −1 s −1 V −1 and achieves a remarkable 385% increase in sensitivity with a limit of detection as low as 7.8 nGy air s −1 . These results mark a significant step toward the development of high-performance and long-lasting lead-free perovskite direct X-ray detectors.

Printable thick junction-based lead-free perovskite single crystal powders for X-ray detection

“…Notably, our preparation method involves SO incorporation and a rapid crystallization process. The obtained Cs 2 AgBiBr 6 device exhibited a high sensitivity at lower bias voltages comparable to those of reported Cs 2 AgBiBr 6 X-ray detectors, 40–45 as shown in Fig. 4d.…”

Mitigation of Parasitic and Drift Capacitance-Induced Nonlinear Current Responses for Stable and Sensitive Perovskite X-ray Detectors

“…Their versatility spans a wide array of applications, including solar cells, photodetectors, and radiation detectors. This popularity is underpinned by their exceptional characteristics, notably their prolonged carrier lifetime, high carrier mobility, and remarkable resilience against defects within their structure. − Specifically, within X-ray detection, metal halide perovskite-based detectors have presented a substantial leap in performance. − Their reported sensitivities have surpassed those of conventional commercial amorphous selenium detectors by an impressive 4 orders of magnitude. , Furthermore, these detectors showcase an extraordinarily low limit of detection, comparable to the ambient environmental background radiation levels, − solidifying their proficiency in discerning extremely minute X-ray signals with exceptional efficiency. The utilization of metal halide perovskite-based X-ray detectors in the context of medical imaging and industrial inspection heralds a paradigm shift in the field.…”