Flexible Linearly Polarized Photodetectors Based on All-Inorganic Perovskite CsPbI3 Nanowires

Polarization-sensitive photodetection has drawn a great deal of research interests, which takes advantage of anisotropy from the lattice structure or the morphology of active material. However, no photodetectors combined these two kinds of anisotropy together for linearly polarized photodetection. Here, a photodetector based on cesium lead iodide (beta-CsPbI3) nanowire array with anisotropic crystal structure is demonstrated. Owing to the crystal structure and morphology anisotropy of the beta-CsPbI3 nanowires, the device exhibited high sensitivity to linearly polarized light with a photocurrent anisotropy ratio of 2.68 and 2.17 on rigid and flexible substrates, respectively, which was much higher than existing linearly polarized photodetectors. In addition, the photocurrent anisotropy ratio of the device on flexible substrate only dropped by 5% after 500 bending cycles, indicating excellent flexibility and folding endurance of flexible CsPbI3 device. The application of anisotropic CsPbI3 nanowires in polarization-sensitive photodetection might provide new functionalities in novel optoelectronic applications.