Facile preparation of fully amorphous bulk PbO-Ga2O3 system for direct photon-charge conversion X-ray detector with low dark current and high photocurrent

Abstract

An amorphous state makes the material free of interface and ensures the overall uniformity of the material and device, to the benefit of large-area electronic devices, such as amorphous silicon and indium gallium zinc oxide display devices and amorphous selenium flat panel detectors. Elements with high atomic number endow the PbO-Ga2O3 system materials with high X-ray absorption coefficients, and wide band gap leading to a low dark current and high signal-to-noise ratio. These advantages are in line with the criteria for a practical X-ray detector development. Herein, the direct photon-charge conversion X-ray detectors based on fully amorphous bulk PbO-Ga2O3 system [(PbO)x(Ga2O3)1-x (x = 0.698, 0.747, 0.761, 0.789)] was fabricated by using high-temperature melt quenching method. Under a fixed electric field of 100 V/mm and X-ray irradiation dose rate of 0.57 μGy ms−1, the dark current as low as 1.1 pA mm−2, photocurrent up to 1600 pA mm−2, signal-to-noise ratio up to 800, comparable sensitivity as 2.02 μC Gy−1 cm−2 of the as fabricated X-ray detector were obtained. All the results suggest that amorphous bulk PbO-Ga2O3 system materials are potential candidates for developing of direct photon-charge conversion X-ray detectors.