Sensitive X-ray detectors made of methylammonium lead tribromide perovskite single crystals

The large mobilities and carrier lifetimes of hybrid perovskite single crystals and the high atomic numbers of Pb, I and Br make them ideal for X-ray and gamma-ray detection. Here, we report a sensitive X-ray detector made of methylammonium lead bromide perovskite single crystals. A record-high mobility–lifetime product of 1.2 × 10–2 cm2 V–1 and an extremely small surface charge recombination velocity of 64 cm s–1 are realized by reducing the bulk defects and passivating surface traps. Single-crystal devices with a thickness of 2–3 mm show 16.4% detection efficiency at near zero bias under irradiation with continuum X-ray energy up to 50 keV. The lowest detectable X-ray dose rate is 0.5 μGyair s–1 with a sensitivity of 80 μC Gy−1air cm–2, which is four times higher than the sensitivity achieved with α-Se X-ray detectors. This allows the radiation dose applied to a human body to be reduced for many medical and security check applications. Single-crystal perovskite devices 2–3 mm thick exhibit 16.4% X-ray detection efficiency with sensitivity four times higher than α-Se X-ray detectors.