A bulk Schottky junction for high-sensitivity portable radiation detectors

The thickness of X-ray detectors needs to reach hundreds of micrometers to absorb X-ray, and therefore, high voltages over tens or hundreds of volts should be applied to extract X-ray-generated carriers. Here, we propose a bulk Schottky junction for X-ray detection using interpenetrated macroporous-carbon electrodes and metal-halide perovskite networks. The X-ray-generated holes are extracted by the macroporous-carbon electrodes under the built-in electric field, while the electrons in the perovskite phase result in a high gain effect. A high sensitivity of 1.42×10⁵ μC Gy_air^-1 cm^-2 and a low detection limit of 48 nGy_air s^-1 at a low voltage of -1 V are achieved. We fabricated a dry battery-powered portable X-ray alarm prototype. The pixel detector shows a decent stability under X-ray exposure, and a spatial resolution of up to 5.0 lp mm^-1, and the detector arrays also exhibit remarkable uniformity, demonstrating its potential application in X-ray imaging.