X-ray-Induced Pyroelectric Effect in a Perovskite Ferroelectric Drives Low Detection Limit Self-Powered Responses

The light-induced pyroelectric effect (LPE) has shown a great promise in the application of optoelectronic devices, especially for self-powered detection and imaging. However, it is quite challenging and scarce to achieve LPE in the X-ray region. For the first time, we report X-ray LPE in a single-phase ferroelectric of (NPA)₂(EA)₂Pb₃Br₁₀ (1, NPA = neopentylamine, EA = ethylamine), adopting a two-dimensional trilayered perovskite motif, which has a large spontaneous polarization of ∼3.7 μC/cm². Its ferroelectricity allows for significant LPE in the wavelength range of ordinary visible light. Strikingly, the X-ray LPE is observed in 1, which endows remarkable self-powered X-ray responses at 0 bias, including sensitivity up to 225 μC Gy^-1 cm^-2 and a low detection limit of ∼83.4 nGy s^-1, being almost 66 times lower than the requirement for medical diagnostics (∼5.5 μGy s^-1). This work not only develops a new mode for X-ray detection but also provides valuable insights for future photoelectric device application.