Radiation Photovoltaics in a 2D Multilayered Chiral‐Polar Halide Perovskite toward Efficient Self‐Driven X‐Ray Detection

2D multilayered organic-inorganic hybrid perovskites (OIHPs) have exhibited bright prospects for high-performance self-driven X-ray detection due to their strong radiation absorption and long carrier transport. However, as an effective tool for self-driven X-ray detection, radiation photovoltaics remain rare, and underdeveloped in multilayered OIHPs. Herein, chirality to induce radiation photovoltaics in 2D multilayered chiral OIHPs is first utilized for efficient self-driven X-ray detection. Specifically, under X-ray irradiation, a multilayered chiral-polar (S-BPEA)2 FAPb2 I7 (1-S, S-BPEA = (S)-1-4-Bromophenylethylammonium, FA = formamidinium) shows remarkable radiation photovoltaics of 0.85 V, which endows 1-S excellent self-driven X-ray detection performance with a considerable sensitivity of 87.8 µC Gyair-1 cm-2 and a detection limit low to 161 nGyair s-1 . Moreover, the sensitivity is high up to 1985.9 µC Gyair-1 cm-2 under 80 V bias, higher than most those of 2D OIHPs. These results demonstrate that chirality-induced radiation photovoltaics is an efficient strategy for self-driven X-ray detection.