Fig. 1: MAPbI3 SC X-ray detector and its figures of merit.
From: Stable perovskite single-crystal X-ray imaging detectors with single-photon sensitivity
a, A 110 µm MAPbI3 SC XPV device with a description of the layers. Scale bar, 200 µm. b, Cross-sectional scanning electron microscopy image of a MAPbI3 SC grown directly on a PTAA/ITO substrate. Scale bar, 50 µm. c, Energy band alignment and operation principle in the XPV mode. d, X-ray imaging of a stencil mask (Supplementary Fig. 3) at doses of 8 nGyair. The inset shows imaging with the GOS scintillator detector. Scale bar, 1 cm. e, DQE dependencies on the dose. The solid black line and points represent the model and experimental data (calculated from d and Supplementary Fig. 4) for MAPbI3 SC, respectively. The red points are experimental data for the GOS scintillator. The green points are amorphous Se data from another work15. The black open squares show the calculated DQE for doses at which X-ray imaging was previously demonstrated with MAPbI3 detectors20. f, Normalized SNR dependence versus time for various bias voltages and device thicknesses. The inset shows the estimated half-life dependence on the bias voltage. The data points represent mean values, whereas the error bars are r.m.s. deviations. They are estimated for 9,600 on/off cycles with a lock-in amplifier (for 960 Hz modulation frequency for X-rays and 10 s integration time). g, MTF dependencies versus spatial frequency for MAPbI3 SC XPV device (solid black line), polycrystalline MAPbI3 (ref. 13) (dashed black line) and commercial detectors, namely, GOS (red line), amorphous Se (ref. 13) (green line) and CdTe SC54 (brown line). The inset shows the through-bottom view on MAPbI3 SC directly grown on a linear array of ITO electrodes. The inner part limited by the dashed lines illustrates the opening of a steel mask aperture. Scale bar, 400 µm. h, Signal intensity profiles were obtained under 50 kVp X-ray irradiation illuminating the steel stencil mask with 100-µm-wide slits, arranged with a spatial frequency of 5 lp mm−1 (blue lines); the experimental points were measured with a GOS commercial scintillator imager with 20 µm pixel pitch (red) and MAPbI3 XPV SC linear detector array with 40 µm line pitch (black). i, MAPbI3 XPV device directly grown on a pixelated ITO substrate. Scale bar, 1 mm.
