Stable perovskite single-crystal X-ray imaging detectors with single-photon sensitivity

• Published in: Nature photonics Vol. 17; no. 6; pp. 510 - 517
• Main Authors: Sakhatskyi, Kostiantyn, Turedi, Bekir, Matt, Gebhard J., Wu, Erfu, Sakhatska, Anastasiia, Bartosh, Vitalii, Lintangpradipto, Muhammad Naufal, Naphade, Rounak, Shorubalko, Ivan, Mohammed, Omar F., Yakunin, Sergii, Bakr, Osman M., Kovalenko, Maksym V.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01.06.2023
• Subjects: Arrays; Bias; Electric potential; Equivalence; Fabrication; Iodides; Ion currents; Lability; Lead compounds; Metal halides; Perovskites; Photons; Photovoltaics; Semiconductor materials; Sensitivity; Sensors; Single crystals; Spatial discrimination; Spatial resolution; Stability; Voltage; X ray detectors; X ray imagery; X-rays
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/s41566-023-01207-y

Abstract A major thrust of medical X-ray imaging is to minimize the X-ray dose acquired by the patient, down to single-photon sensitivity. Such characteristics have been demonstrated with only a few direct-detection semiconductor materials such as CdTe and Si; nonetheless, their industrial deployment in medical diagnostics is still impeded by elaborate and costly fabrication processes. Hybrid lead halide perovskites can be a viable alternative owing to their facile solution growth. However, hybrid perovskites are unstable under high-field biasing in X-ray detectors, owing to structural lability and mixed electronic–ionic conductivity. Here we show that both single-photon-counting and long-term stable performance of perovskite X-ray detectors are attained in the photovoltaic mode of operation at zero-voltage bias, employing thick and uniform methylammonium lead iodide single-crystal films (up to 300 µm) and solution directly grown on hole-transporting electrodes. The operational device stability exceeded one year. Detection efficiency of 88% and noise-equivalent dose of 90 pGy air are obtained with 18 keV X-rays, allowing single-photon-sensitive, low-dose and energy-resolved X-ray imaging. Array detectors demonstrate high spatial resolution up to 11 lp mm −1 . These findings pave the path for the implementation of hybrid perovskites in low-cost, low-dose commercial detector arrays for X-ray imaging.