Ultrawide-Bandgap Rb2AgCl3 Perovskite Single Crystals Enabling Self-Powered Solar-Blind UV Polarization-Sensitive Photodetection for Intelligent Imaging and Encryption

Solar-blind ultraviolet polarization detection is critically hindered by the intrinsic isotropy, complex fabrication, and insufficient polarization sensitivity of conventional ultrawide-bandgap (UWBG) semiconductors such as Ga 2 O 3 and h-BN. Here, we break this deadlock by introducing a rationally designed lead-free perovskite analogue, one-dimensional Rb 2 AgCl 3 single crystals, which were synthesized via a spatially confined cooling method. Its unique chain-like lattice endows an ultrawide bandgap of 4.83 eV, exceptional thermal stability up to 934 K, and pronounced in-plane optical anisotropy. Enabled by these attributes, a Schottky-junction self-powered photodetector achieves unprecedented solar-blind ultraviolet performance: a responsivity of 0.2 A/W, specific detectivity of 3.46 × 10 12 Jones, external quantum efficiency of 96%, ultrafast response of 7.9/17.5 µs, and a record dichroic ratio of 15.8 at 255 nm. These metrics not only surpass all reported perovskite-based devices but also rival, and even outperform, state-of-the-art UWBG semiconductors. Furthermore, the detector enables high-fidelity polarization imaging, convolutional neural network integration with >99% recognition accuracy, and a 6 × 6 array encryption system based on physically unclonable function keys. This work elevates low-dimensional lead-free perovskites from mere substitutes to genuine rivals, establishing a transformative platform for intelligent, self-powered solar-blind optoelectronics.