Chiral Polar Dion‐Jacobson Perovskites Enable High‐Performance Self‐Powered Circularly Polarized Light Detection via the Pyro‐Phototronic Effect

Circularly polarized light (CPL) detection requires simultaneous handedness recognition and signal amplification. The pyro‐phototronic effect (PPE) offers a powerful route to amplify photodetection performance by harnessing photo‐thermal‐polarization coupling, yet its marriage with CPL selectivity remains unexplored in 2D lead‐based Dion–Jacobson (DJ) perovskites. Herein, two novel 2D DJ‐type hybrid perovskites ( R/S ‐4PE)PbBr 4 ( 1‐R/1‐S , R/S ‐4PE = R/S ‐4‐pyridine‐ethylamine) crystals with the P 2 1 chiral polar space group are first constructed for high‐performance self‐powered CPL detection, exploiting the PPE. Specifically, 1‐R exhibits exceptionally low octahedral distortion (Δ d = 2.6 × 10 −4 ) and near‐planar inorganic layers (Pb─Br─Pb ≈ 170.5°), and facilitates efficient carrier transportation with a large carrier mobility lifetime ( μ τ) product (3.5 × 10 −4 cm 2 V −1 ). PPE caused by spontaneous polarization ( P s ) endows 1‐R with ultra‐broadband response from visible light to near‐infrared‐II region (405 – 1625 nm). Furthermore, leveraging the synergy between chirality‐induced spin selectivity and PPE, self‐powered CPL detection based on PPE with a high anisotropic factor ( g Iph ) of 0.49 at 405 nm is successfully achieved, exceeding most CPL detection materials (usually ≤ 0.3). This study first realized the PPE in lead‐based DJ‐type perovskites, showcasing ultra‐broadband self‐driven pyro‐phototronic responses and high‐efficiency CPL detection enabled by PPE, which promotes the development of new CPL detectors.