Multilayered 2D Cesium‐Based Hybrid Perovskite with Strong Polarization Sensitivity: Dimensional Reduction of CsPbBr3

Abstract

Three-dimensional (3D) perovskite CsPbBr 3 has recently taken a blooming position for optoelectronic applications. However, due to the lack of natural anisotropy of optical attributes, it is a great challenge to fulfil polarization-sensitive photodetection. Here, for the first time, we exploited dimensionality reduction of CsPbBr 3 to tailor 2D multilayered hybrid perovskite, (TRA) 2 CsPb 2 Br 7 (1, where TRA is (carboxy)cyclohexylmethylammonium), serving as a potential polarized-light detecting candidate. Its unique quantum-confined 2D structure results in intrinsic anisotropy of electrical conductivity, optical absorbance and polarization-dependent responses. Particularly, it exhibits remarkable dichroism with the photocurrent ratio ( I pc / I pa ) of ~ 2.1, being much higher than that of isotropic CsPbBr 3 crystal and reported CH 3 NH 3 PbI 3 nanowire ( ~ 1.3), which reveals its great potentials for polarization-sensitive photodetection. Further, crystal-based detectors of 1 show fascinating responses to the polarized-light, including high detectivity (>10 10 Jones), fast responding time ( ~ 300μs) and sizeable on/off current ratios (>10 4 ). To our best knowledge, this is the first study on 2D Cs-based hybrid perovskite exhibiting strong polarization-sensitivity. The work highlights an effective pathway to explore new polarization-sensitive candidates for hybrid perovskites and promotes their future electronic applications.