Polar hybrid perovskites (HPs) can achieve steady-state self-powered X-ray detection via the bulk photovoltaic effect (BPVE), but effective strategies to induce BPVE remain scarce. Herein, using one-dimensional nonpolar HP (4-MeP)4Pb3Br10 (1, 4-MeP = 4-methylaniline) as a template, we successfully synthesized an unprecedented two-dimensional (2D) polar HP (4-SP)4Pb3Br10·2H2O (2, 4-SP = 4-aminothiophenol) by replacing the C atom in the 4-MeP ligand with an S atom possessing lone pair electrons. Specifically, lone pair electrons on S cause structural distortion and ultimately induce BPVE in 2. Therefore, 2 achieves efficient self-powered X-ray detection with a high sensitivity of 271.8 μC Gy–1 cm–2 under 22 keV average X-ray energy. Meanwhile, it also exhibits a record-breaking sensitivity of 1.1 × 104 μC Gy–1 cm–2 under 31.8 V mm–1 in all 2D single-layer HPs. Importantly, 2 possesses strong ion-migration inhibition, high radiation resistance, and excellent storage stability. Our work provides a strategy for the development and application of HPs with BPVE.
Yang et al. (2026) studied this question.