Large and Dense Organic-Inorganic Hybrid Perovskite CH 3 NH 3 PbI 3 Wafer Fabricated by One-Step Reactive Direct Wafer Production with High X-ray Sensitivity.

Lead halide perovskites with good optoelectronic properties and high attenuation of high-energy radiation are great candidates for X-ray radiation detectors. Large area, dense, and thick films or wafers are a prerequisite for these applications. In this paper, a one-step heat-assisted high-pressure press method is developed to directly prepare a large (the largest has a diameter of 80 mm) and thickness- and shape-controlled phase-pure organic-inorganic hybrid CH ₃ NH ₃ PbI ₃ wafer of densely packed large microcrystals from raw powder materials. Meanwhile, this method uses no solvent to achieve essentially 100% material utilization. The obtained wafers show good ambipolar carrier mobilities of ∼20 cm ² V ^-1 s ^-1 and a μτ product as high as 3.84 × 10 ^-4 cm ² V ^-1 . Under an X-ray source using an acceleration voltage of 40 kV, the perovskite wafer-based X-ray detector shows an X-ray sensitivity as large as 1.22 × 10 ⁵ μC Gy _air ^-1 cm ^-2 under a 10 V bias, the highest reported for any perovskite material. The method provides a convenient strategy for producing large perovskite wafers with good optoelectronic properties, which will facilitate the development of large perovskite devices.