High Sensitivity X‐Ray Detectors with Low Degradation Based on Deuterated Halide Perovskite Single Crystals

Methylammonium lead single crystal (MAPbI₃ SC) possesses superior optoelectronic properties and low manufacturing cost, making it an ideal candidate for X-ray detection. However, the ionic migration of the perovskites usually leads to instability, dark current drift, and hysteresis of the detector, limiting their applications in well-established technologies. Here, a series of X-ray detectors of MAPbI₃ SCs are reported with different degrees of deuteration (D_xMAPbI₃, x = 0, 0.15, 0.75, 0.99). By controlling the content of deuterium (D) in organic cations, the sensitivity, detection limits, ion migration, and resistivity of the detector can be controlled, thereby improving its performance. Due to stronger hydrogen bonds (N─D···I), the ion activation energy significantly increases to 886 meV. Consequently, the D_0.99MAPbI₃ SC detector shows more than five-fold enhancement, achieving a record-high mobility-lifetime (µτ) product of 5.39 × 10^-2 cm² V^-1, with an ultrahigh sensitivity of 2.18 × 10⁶ µC Gy^-1 cm^-2 under 120 keV hard X-ray and a low detection limit of 4.8 nGy_air s^-1, as well as long-term stability. The study provides a straightforward strategy for constructing ultrasensitive X-ray detection and imaging systems based on perovskite SCs.