Face-/Edge-Shared 3D Perovskitoid Single Crystals with Suppressed Ion Migration for Stable X-Ray Detector

Although three-dimensional metal halide perovskites are promising candidates for direct X-ray detection, the ion migration of perovskites seriously affects the detector stability. Herein, face-/edge-shared 3D heterometallic glycinate hybrid perovskitoid Pb₂CuGly₂X₄ (Gly = -O₂C-CH₂-NH₂; X = Cl, Br) single crystals (SCs), in which the adjacent lead halide layers are linked by large-sized Cu(Gly)₂ pillars, are synthesized in water. The Cu(Gly)₂ pillars in combination with face-/edge-shared inorganic skeleton are found able to synergistically suppress the ion migration, delivering a high ion migration activation energy (E_a) of 1.06 eV. The Pb₂CuGly₂Cl₄ SC X-ray detector displays extremely low dark current drift of 1.20 × 10^-9 nA mm^-1 s^-1 V^-1 under high electric field (120 V mm^-1) and continuous X-ray irradiation (2.86 Gy), and a high sensitivity of 9,250 μC Gy^-1 cm^-2 is also achieved. More excitingly, the Pb₂CuGly₂Cl₄ nanocrystal can be easily dispersed in water and directly blade-coated on thin-film transistor (TFT) array substrate, and the obtained Pb₂CuGly₂Cl₄-based TFT array detector offers an X-ray imaging capability with spatial resolution of 2.2 lp mm^-1.