High-sensitivity high-resolution X-ray imaging with soft-sintered metal halide perovskites

Sarah Deumel,Eric Meulenkamp,Judith E Huerdler,Joris Maas,Santhosh Shanmugam,Sandro F Tedde,Bart Peeters,Oliver Schmidt,Gerwin Gelinck,Albert Van Breemen,Roy Verbeek,Marisé García-Batlle,Osbel Almora,Wolfgang Heiss,Manognya Acharya,Germà Garcia-Belmonte,Antonio Guerrero,Hylke Akkerman

doi:10.1038/s41928-021-00644-3

Abstract

To realize the potential of artificial intelligence in medical imaging, improvements in imaging capabilities are required, as well as advances in computing power and algorithms. Hybrid inorganic–organic metal halide perovskites, such as methylammonium lead triiodide (MAPbI3), offer strong X-ray absorption, high carrier mobilities (µ) and long carrier lifetimes (τ), and they are promising materials for use in X-ray imaging. However, their incorporation into pixelated sensing arrays remains challenging. Here we show that X-ray flat-panel detector arrays based on microcrystalline MAPbI3 can be created using a two-step manufacturing process. Our approach is based on the mechanical soft sintering of a freestanding absorber layer and the subsequent integration of this layer on a pixelated backplane. Freestanding microcrystalline MAPbI3 wafers exhibit a sensitivity of 9,300 µC Gyair–1 cm–2 with a μτ product of 4 × 10–4 cm2 V–1, and the resulting X-ray imaging detector, which has 508 pixels per inch, combines a high spatial resolution of 6 line pairs per millimetre with a low detection limit of 0.22 nGyair per frame.

Highlights

The use of artificial intelligence (AI) in medical imaging is steadily growing[1,2,3]
Our approach separates the fabrication of an X-ray absorber layer with a thickness of several hundreds of micrometres from integration onto the backplane
We have reported a two-step manufacturing process for MAPbI3 X-ray flat-panel detectors based on the mechanical sintering of a freestanding absorber layer and integration of this layer on a pixelated backplane

Summary

10 Klein rule

To an electrical field of ±0.2 V μm−1. The electrical field was at first decreased from 0 to −0.200 V μm−1 in steps of 0.001 V μm−1; thereafter, it was increased from 0 to +0.2 V μm−1. In the current density versus electrical field (J–E) plot (Fig. 3a), the dark current density reaches the maximum value of 8.40 × 10–4 mA cm−2 for negative fields, the so-called reverse bias direction, and 1.98 × 10–3 mA cm−2 for positive (forward) bias. (according to the IEC 61267:2005 standard) X-ray spectrum and a dose rate of 213 μGyair s−1 at different bias voltages was captured with a Keithley 2400 source meter. This results in the maximum value of 9,300 μC Gyair−1 cm−2 for the sensitivity of our wafer at an electrical field of 0.17 V μm−1 (Fig. 3b).

Conclusions

Findings

Methods