Centimeter-size single crystal of a lead-free double perovskite for broad-spectrum polarization-sensitive detection.

Two-dimensional (2D) lead-based hybrid perovskites with highly intrinsic anisotropy and entertaining semiconductor properties are well suited for polarization-sensitive photodetection. Nonetheless, their chemical instability and environmental hazards hinder their further application. Recenly, 2D double perovskites have received much attention as excellent green alternatives to lead-based perovskites. However, the application of 2D double perovskite in broad-spectrum polarization-sensitive detection has not been explored. In this work, we first grew centimeter-sized crystals (11 × 3 × 1 mm³) of 2D hybrid double perovskite (IPA)₄AgBiI₈ (IPA is iodopropylamine) with narrow bandgap of Eg = 1.87 eV. Remarkably, the single-crystal photodetectors of (IPA)₄AgBiI₈ show broad-spectrum polarization-sensitive response, even at 660 nm, with a large dichroism ratio (I_phc/I_phb ≈ 1.23), a large detectivity up to ∼10¹⁰ Jones, and a relatively rapid response time (∼450 μs). All these outstanding features combine to produce (IPA)₄AgBiI₈, an excellent polarized photodetector material. This work introduces a novel 2D hybrid double perovskite material for broad-spectrum polarization-sensitive photodetection. [ABSTRACT FROM AUTHOR]