Overcoming the chiroptical activity-photoelectricity trade-off via the construction of multilayered Cs-based chiral-polar perovskite
Detection of circularly polarized light (CPL) is crucial for advancing next-generation chiral optoelectronic applications, where a large photocurrent dissymmetry factor (g_Iph) is essential for accurate polarization discrimination. Chiral hybrid perovskites (CHPs) have emerged as promising CPL-active materials owing to their intrinsic spin-orbit coupling and chiroptical properties. However, an intrinsic conflict between g_Iph and photocurrent response remains a major bottleneck in current CHP-based devices. Low-dimensional CHPs typically suffer from limited carrier mobility, while multilayered structures improve carrier transport but generally reduce the chiral component, thereby reducing chiroptical activity and g_Iph. Herein, we report a Cs-based multilayered chiral-polar perovskite, (R-β-MPA)PACsPb2Br7 (1R, MPA=methylphenethylammonium, PA=propylammonium). The distinctive chiral-polar photovoltaic effect in 1R benefits spin-selective carrier separation and collection, and the resulting device achieves self-powered CPL detection with a high g_Iph of 0.5 and maintains excellent polarization selectivity even at ultralow light intensities of 62 nW cm−2. Meanwhile, the multilayered framework enables high responsivity of 71 mA W−1 and detectivity of 6×10^12 Jones (1 Jones = 1 cm Hz^(1/2) W−1) even at zero bias. This work provides a rational design strategy to achieve chiral optoelectronic materials with a high dissymmetry factor and photocurrent response.