Highly sensitive X-ray detectors using printable organometallic perovskites with large polycrystalline grains
Journal
Nature
Date
2017.10.05
Abstract
Digital flat detectors playing a central role in the evolution of medical X-ray imaging procedures are currently in need of low-dose operation to reduce radiation-induced risks to a human body. Solution-processed organic-inorganic hybrid perovskites enable to fabricate sensitive detectors for the medical application energy range between 20 and 140 keV. Here, we present a disruptive polycrystalline CH3NH3PbI3 that is printable for thick films on large substrates, exhibiting average grain size 20？30 ？m with a sharply-faceted morphology. A combined benefit of large charge carrier mobility-lifetime products of 1.0？1.46 ？ 10？4 cm2 V？1, corresponding carrier diffusion length exceeding 18 ？m, and high absorptivity over the full medical X-ray energy domain is represented as good X-ray sensitivities of 87？174 ？C mGyair？1 cm？3 under irradiation with a 100 kVp bremsstrahlung source, which are at least one order higher than the sensitivities achieved with a-Se detectors. By embedding 700-？m-thick perovskites and additional polyimide-perovskite composite interlayers, we demonstrate a 10 cm ？ 10 cm X-ray image to prove the feasibility of our all-solution-based detector concept.