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Halide perovskites are promising candidates for soft X-ray detection (<80 keV) owing to their high X-ray absorption coefficient, resistivity, and mobility lifetime product. However, the lack of large high-quality single crystals (SCs) renders it challenging to manufacture robust hard X-ray imaging systems (>100 keV) with a low detection limit and stable dark current. Herein, high-quality inch-size two-dimensional (2D) Cs 3 Bi 2 Br 9 (CBB) single crystals are grown from a melt via the Bridgman method. The crystal quality is enhanced by eliminating inclusions of CsBr-rich phases and restraining the trap-state density, leading to an enhanced resistivity of 1.41 × 10 12 Ω cm and a mobility lifetime product of 8.32 × 10 −4 cm 2 V −1 . The Au/CBB/Au singlecrystal device exhibits a high sensitivity of 1705 μC Gy air −1 cm −2 in all-inorganic bismuth-based perovskites and an ultralow detection limit of 0.58 nGy air s −1 in all of the bismuth-based perovskites for 120 keV hard X-ray detection. The CBB detector exhibits high work stability with an ultralow dark current drift of 2.8 × 10 −10 nA cm −1 s −1 V −1 and long-term air environment reliability under a high electric field of 10 000 V cm −1 owing to the ultrahigh ionic activation energy of the 2D structure. The proposed robust imaging system based on CBB SC is a promising tool for X-ray medical imaging and diagnostics. KEYWORDS: lead-free perovskites, two-dimensional perovskites, Cs 3 Bi 2 Br 9 single crystal, ultralow detection limit, X-ray imaging

With the fast development of integrated circuit technology and internet of things, sensors with multifunctional characteristics are desperately needed. This work presents an integrated electromagnetic‐triboelectric active sensor (ETAS) for simultaneous detection of multiple mechanical triggering signals. The good combination of a contact‐separation mode triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG) realizes the complement of their individual advantages. The theoretical calculation and analysis of EMG and TENG are performed to understand the relationship between their output and the external mechanical signals. The experimental results show that the output voltage of TENG part is suitable to detect the magnitude of the external triggering force with a sensitivity of about 2.01 V N−1. Meanwhile, the output current of EMG part is more appropriate to reflect the triggering velocity and the sensitivity is about 4.3 mA (m s−1)−1. Moreover, both the TENG part and the EMG part exhibit good stabilities after more than 20 000 cycles of force loading and unloading. One ETAS that can record the typing behavior of the finger precisely is demonstrated. In addition, the TENG part can harvest the mechanical energy during typing for possible powering of tiny electronics. This ETAS has promising applications in complex human–machine interface, personal identification, and security system.

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