Polar Hybrid Perovskite Obtained by Induction of Lone Pair Electrons toward Efficient and Stable Self-Powered X-ray Detection

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) 4 Pb 3 Br 10 ( 1, 4-MeP = 4-methylaniline) as a template, we successfully synthesized an unprecedented two-dimensional (2D) polar HP (4-SP) 4 Pb 3 Br 10 ·2H 2 O ( 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 × 10 4 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.