Catalyst‐Free and Morphology‐Controlled Growth of 2D Perovskite Nanowires for Polarized Light Detection

Abstract Ruddleson–Popper (RP) perovskites have emerged as a class of material inheriting the superior optoelectronic properties of two materials: perovskites and 2D materials. The large exciton binding energy and natural quantum well structure not only make these materials ideal platforms to study light–matter interactions but also render them suitable for fabrication of various functional optoelectronic devices. Nanoscale structuring and morphology control have led to semiconductors with enhanced functionalities. Nanowires of semiconducting materials are extensively used for important applications like lasing and sensing. However, catalyst and template‐free scalable growth of nanowires of 2D perovskites has remained elusive. In this paper, a facile approach for morphology‐controlled growth of nanowires of 2D perovskite, (BA)₂PbI₄, is demonstrated. Additionally, it is shown that the photoluminescence (PL) from the nanowires is highly polarized with a polarization ratio as large as ≈0.73, which is one of the largest reported for perovskites. It is further shown that the photocurrent from the hybrid nanowire/graphene device is also sensitive to the polarization of the incident light with the photocurrent anisotropy ratio of ≈3.62 (much larger than the previously reported value of 2.68 for perovskites), thus demonstrating the potential of these nanowires as highly efficient photodetectors for polarized light.